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https://github.com/lupyuen/pinephone-lvgl-zig
LVGL for PinePhone (and WebAssembly) with Zig and Apache NuttX RTOS
https://github.com/lupyuen/pinephone-lvgl-zig
lvgl nuttx pinephone wasm zig
Last synced: 28 days ago
JSON representation
LVGL for PinePhone (and WebAssembly) with Zig and Apache NuttX RTOS
- Host: GitHub
- URL: https://github.com/lupyuen/pinephone-lvgl-zig
- Owner: lupyuen
- License: apache-2.0
- Created: 2023-01-20T10:10:24.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2023-08-10T04:00:34.000Z (over 1 year ago)
- Last Synced: 2024-11-08T03:36:43.895Z (about 1 month ago)
- Topics: lvgl, nuttx, pinephone, wasm, zig
- Language: Zig
- Homepage: https://lupyuen.github.io/articles/lvgl4
- Size: 19.5 MB
- Stars: 20
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
- awesome-zig - lupyuen/pinephone-lvgl-zig
README
# LVGL for PinePhone (and WebAssembly) with Zig and Apache NuttX RTOS
Read the articles...
- ["NuttX RTOS for PinePhone: Feature Phone UI in LVGL, Zig and WebAssembly"](https://lupyuen.github.io/articles/lvgl4)
- ["(Possibly) LVGL in WebAssembly with Zig Compiler"](https://lupyuen.github.io/articles/lvgl3)
- ["NuttX RTOS for PinePhone: Boot to LVGL"](https://lupyuen.github.io/articles/lvgl2)
- ["Build an LVGL Touchscreen App with Zig"](https://lupyuen.github.io/articles/lvgl)
Can we build an __LVGL App in Zig__ for PinePhone... That will run on Apache NuttX RTOS?
Can we preview a PinePhone App with __Zig, LVGL and WebAssembly__ in a Web Browser? To make the UI Coding a little easier?
Let's find out!
# LVGL Zig App
Let's run this LVGL Zig App on PinePhone...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/c7a33f1fe3af4babaa8bc5502ca2b719ae95c2ca/lvgltest.zig#L55-L89
_How is createWidgetsWrapped called?_
`createWidgetsWrapped` will be called by the LVGL Widget Demo [`lv_demo_widgets`](https://github.com/lvgl/lvgl/blob/v8.3.3/demos/widgets/lv_demo_widgets.c#L96-L198), which we'll replace by this Zig version...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/c7a33f1fe3af4babaa8bc5502ca2b719ae95c2ca/lvgltest.zig#L32-L41
_Where's the Zig Wrapper for LVGL?_
Our Zig Wrapper for LVGL is defined here...
- [lvgl.zig](https://github.com/lupyuen/pinephone-lvgl-zig/blob/main/lvgl.zig)
We also have a version of the LVGL Zig Code that doesn't call the Zig Wrapper...
- [lvgltest.zig](https://github.com/lupyuen/pinephone-lvgl-zig/blob/c7a33f1fe3af4babaa8bc5502ca2b719ae95c2ca/lvgltest.zig#L91-L126)
# Build LVGL Zig App
NuttX Build runs this GCC Command to compile [lv_demo_widgets.c](https://github.com/lvgl/lvgl/blob/v8.3.3/demos/widgets/lv_demo_widgets.c#L96-L198) for PinePhone...
```bash
$ make --trace
...
cd $HOME/PinePhone/wip-nuttx/apps/graphics/lvgl
aarch64-none-elf-gcc
-c
-fno-common
-Wall
-Wstrict-prototypes
-Wshadow
-Wundef
-Werror
-Os
-fno-strict-aliasing
-fomit-frame-pointer
-g
-march=armv8-a
-mtune=cortex-a53
-isystem $HOME/PinePhone/wip-nuttx/nuttx/include
-D__NuttX__
-pipe
-I $HOME/PinePhone/wip-nuttx/apps/graphics/lvgl
-I "$HOME/PinePhone/wip-nuttx/apps/include"
-Wno-format
-Wno-unused-variable
"-I./lvgl/src/core"
"-I./lvgl/src/draw"
"-I./lvgl/src/draw/arm2d"
"-I./lvgl/src/draw/nxp"
"-I./lvgl/src/draw/nxp/pxp"
"-I./lvgl/src/draw/nxp/vglite"
"-I./lvgl/src/draw/sdl"
"-I./lvgl/src/draw/stm32_dma2d"
"-I./lvgl/src/draw/sw"
"-I./lvgl/src/draw/swm341_dma2d"
"-I./lvgl/src/font"
"-I./lvgl/src/hal"
"-I./lvgl/src/misc"
"-I./lvgl/src/widgets"
"-DLV_ASSERT_HANDLER=ASSERT(0);"
lvgl/demos/widgets/lv_demo_widgets.c
-o lvgl/demos/widgets/lv_demo_widgets.c.Users.Luppy.PinePhone.wip-nuttx.apps.graphics.lvgl.o
```
We'll copy the above GCC Options to the Zig Compiler and build this Zig Program for PinePhone...
- [lvgltest.zig](https://github.com/lupyuen/pinephone-lvgl-zig/blob/main/lvgltest.zig)
Here's the Shell Script...
```bash
## Build the LVGL Zig App
function build_zig {
## Go to LVGL Zig Folder
pushd ../pinephone-lvgl-zig
git pull
## Check that NuttX Build has completed and `lv_demo_widgets.*.o` exists
if [ ! -f ../apps/graphics/lvgl/lvgl/demos/widgets/lv_demo_widgets.*.o ]
then
echo "*** Error: Build NuttX first before building Zig app"
exit 1
fi
## Compile the Zig App for PinePhone
## (armv8-a with cortex-a53)
## TODO: Change ".." to your NuttX Project Directory
zig build-obj \
--verbose-cimport \
-target aarch64-freestanding-none \
-mcpu cortex_a53 \
-isystem "../nuttx/include" \
-I "../apps/include" \
-I "../apps/graphics/lvgl" \
-I "../apps/graphics/lvgl/lvgl/src/core" \
-I "../apps/graphics/lvgl/lvgl/src/draw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/arm2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/pxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/vglite" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sdl" \
-I "../apps/graphics/lvgl/lvgl/src/draw/stm32_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/swm341_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/font" \
-I "../apps/graphics/lvgl/lvgl/src/hal" \
-I "../apps/graphics/lvgl/lvgl/src/misc" \
-I "../apps/graphics/lvgl/lvgl/src/widgets" \
lvgltest.zig
## Copy the compiled app to NuttX and overwrite `lv_demo_widgets.*.o`
## TODO: Change ".." to your NuttX Project Directory
cp lvgltest.o \
../apps/graphics/lvgl/lvgl/demos/widgets/lv_demo_widgets.*.o
## Return to NuttX Folder
popd
}
## Download the LVGL Zig App
git clone https://github.com/lupyuen/pinephone-lvgl-zig
## Build NuttX for PinePhone
cd nuttx
make -j
## Build the LVGL Zig App
build_zig
## Link the LVGL Zig App with NuttX
make -j
```
[(Original Build Script)](https://gist.github.com/lupyuen/aa1f5c0c45e6029b10e5e2f955d8386c)
[(Updated Build Script)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/2e1c97e49e51b1cbbe0964a9512eba141d0dd09f/build.sh#L192-L223)
[(NuttX Build Files)](https://github.com/lupyuen/pinephone-lvgl-zig/releases/tag/nuttx-build-files)
And our LVGL Zig App runs OK on PinePhone!
# Simulate PinePhone UI with Zig, LVGL and WebAssembly
Read the article...
- ["(Possibly) LVGL in WebAssembly with Zig Compiler"](https://lupyuen.github.io/articles/lvgl3)
We're now building a __Feature Phone UI__ for NuttX on PinePhone...
Can we simulate the Feature Phone UI with __Zig, LVGL and WebAssembly__ in a Web Browser? To make the UI Coding a little easier?
We have previously created a simple __LVGL App with Zig__ for PinePhone...
- [pinephone-lvgl-zig](https://github.com/lupyuen/pinephone-lvgl-zig)
Zig natively supports __WebAssembly__...
- [WebAssembly on Zig](https://ziglang.org/documentation/master/#WebAssembly)
So we might run __Zig + JavaScript__ in a Web Browser like so...
- [WebAssembly With Zig in a Web Browser](https://dev.to/sleibrock/webassembly-with-zig-pt-ii-ei7)
But LVGL doesn't work with JavaScript yet. LVGL runs in a Web Browser by compiling with Emscripten and SDL...
- [LVGL with Emscripten and SDL](https://github.com/lvgl/lv_web_emscripten)
Therefore we shall do this...
1. Use Zig to compile LVGL from C to WebAssembly [(With `zig cc`)](https://github.com/lupyuen/zig-bl602-nuttx#zig-compiler-as-drop-in-replacement-for-gcc)
1. Use Zig to connect the JavaScript UI (canvas rendering + input events) to LVGL WebAssembly [(Like this)](https://dev.to/sleibrock/webassembly-with-zig-pt-ii-ei7)
# WebAssembly Demo with Zig and JavaScript
We can run __Zig (WebAssembly) + JavaScript__ in a Web Browser like so...
- [WebAssembly With Zig in a Web Browser](https://dev.to/sleibrock/webassembly-with-zig-pt-ii-ei7)
Let's run a simple demo...
- [demo/mandelbrot.zig](demo/mandelbrot.zig): Zig Program that compiles to WebAssembly
- [demo/game.js](demo/game.js): JavaScript that loads the Zig WebAssembly
- [demo/demo.html](demo/demo.html): HTML that calls the JavaScript
To compile Zig to WebAssembly...
```bash
git clone --recursive https://github.com/lupyuen/pinephone-lvgl-zig
cd pinephone-lvgl-zig
cd demo
zig build-lib \
mandelbrot.zig \
-target wasm32-freestanding \
-dynamic \
-rdynamic
```
[(According to this)](https://ziglang.org/documentation/master/#Freestanding)
This produces the Compiled WebAssembly [`mandelbrot.wasm`](mandelbrot.wasm).
Start a Local Web Server. [(Like Web Server for Chrome)](https://chrome.google.com/webstore/detail/web-server-for-chrome/ofhbbkphhbklhfoeikjpcbhemlocgigb)
Browse to `demo/demo.html`. We should see the Mandelbrot Set yay!
# Import JavaScript Functions into Zig
_How do we import JavaScript Functions into our Zig Program?_
This is documented here...
- [WebAssembly on Zig](https://ziglang.org/documentation/master/#WebAssembly)
In our Zig Program, this is how we import and call a JavaScript Function: [demo/mandelbrot.zig](demo/mandelbrot.zig)
```zig
/// Import `print` Function from JavaScript
extern fn print(i32) void;
...
// Test printing to JavaScript Console.
// Warning: This is slow!
if (iterations == 1) { print(iterations); }
```
We define the JavaScript Function `print` when loading the WebAssembly Module in our JavaScript: [demo/game.js](demo/game.js)
```javascript
// Export JavaScript Functions to Zig
let importObject = {
// JavaScript Environment exported to Zig
env: {
// JavaScript Print Function exported to Zig
print: function(x) { console.log(x); }
}
};
// Load the WebAssembly Module
// https://developer.mozilla.org/en-US/docs/WebAssembly/JavaScript_interface/instantiateStreaming
async function bootstrap() {
// Store references to WebAssembly Functions and Memory exported by Zig
Game = await WebAssembly.instantiateStreaming(
fetch("mandelbrot.wasm"),
importObject
);
// Start the Main Function
main();
}
// Start the loading of WebAssembly Module
bootstrap();
```
_Will this work for passing Strings and Buffers as parameters?_
Nope, the parameter will be passed as a number. (Probably a WebAssembly Data Address)
To pass Strings and Buffers between JavaScript and Zig, see [daneelsan/zig-wasm-logger](https://github.com/daneelsan/zig-wasm-logger).
# Compile Zig LVGL App to WebAssembly
_Does our Zig LVGL App lvgltest.zig compile to WebAssembly?_
Let's take the earlier steps to compile our Zig LVGL App `lvgltest.zig`. To compile for WebAssembly, we change...
- `zig build-obj` to `zig build-lib`
- Target becomes `-target wasm32-freestanding`
- Remove `-mcpu`
- Add `-dynamic` and `-rdynamic`
Like this...
```bash
## Compile the Zig App for WebAssembly
## TODO: Change ".." to your NuttX Project Directory
zig build-lib \
--verbose-cimport \
-target wasm32-freestanding \
-dynamic \
-rdynamic \
-isystem "../nuttx/include" \
-I "../apps/include" \
-I "../apps/graphics/lvgl" \
-I "../apps/graphics/lvgl/lvgl/src/core" \
-I "../apps/graphics/lvgl/lvgl/src/draw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/arm2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/pxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/vglite" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sdl" \
-I "../apps/graphics/lvgl/lvgl/src/draw/stm32_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/swm341_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/font" \
-I "../apps/graphics/lvgl/lvgl/src/hal" \
-I "../apps/graphics/lvgl/lvgl/src/misc" \
-I "../apps/graphics/lvgl/lvgl/src/widgets" \
lvgltest.zig
```
[(According to this)](https://ziglang.org/documentation/master/#Freestanding)
[(NuttX Build Files)](https://github.com/lupyuen/pinephone-lvgl-zig/releases/tag/nuttx-build-files)
OK no errors, this produces the Compiled WebAssembly `lvgltest.wasm`.
Now we tweak [`lvgltest.zig`](lvgltest.zig) for WebAssembly, and call it [`lvglwasm.zig`](lvglwasm.zig)...
```bash
## Compile the Zig App for WebAssembly
## TODO: Change ".." to your NuttX Project Directory
zig build-lib \
--verbose-cimport \
-target wasm32-freestanding \
-dynamic \
-rdynamic \
-isystem "../nuttx/include" \
-I "../apps/include" \
-I "../apps/graphics/lvgl" \
-I "../apps/graphics/lvgl/lvgl/src/core" \
-I "../apps/graphics/lvgl/lvgl/src/draw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/arm2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/pxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/vglite" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sdl" \
-I "../apps/graphics/lvgl/lvgl/src/draw/stm32_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/swm341_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/font" \
-I "../apps/graphics/lvgl/lvgl/src/hal" \
-I "../apps/graphics/lvgl/lvgl/src/misc" \
-I "../apps/graphics/lvgl/lvgl/src/widgets" \
lvglwasm.zig
```
[(According to this)](https://ziglang.org/documentation/master/#Freestanding)
[(NuttX Build Files)](https://github.com/lupyuen/pinephone-lvgl-zig/releases/tag/nuttx-build-files)
(We removed our Custom Panic Handler, the default one works fine for WebAssembly)
This produces the Compiled WebAssembly [`lvglwasm.wasm`](lvglwasm.wasm).
Start a Local Web Server. [(Like Web Server for Chrome)](https://chrome.google.com/webstore/detail/web-server-for-chrome/ofhbbkphhbklhfoeikjpcbhemlocgigb)
Browse to our HTML [`lvglwasm.html`](lvglwasm.html). Which calls our JavaScript [`lvglwasm.js`](lvglwasm.js) to load the Compiled WebAssembly.
Our JavaScript [`lvglwasm.js`](lvglwasm.js) calls the Zig Function `lv_demo_widgets` that's exported to WebAssembly by our Zig App [`lvglwasm.zig`](lvglwasm.zig).
But the WebAssembly won't load because we haven't fixed the WebAssembly Imports...
# Fix WebAssembly Imports
_What happens if we don't fix the WebAssembly Imports in our Zig Program?_
Suppose we forgot to import `puts()`. JavaScript Console will show this error when the Web Browser loads our Zig WebAssembly...
```text
Uncaught (in promise) LinkError:
WebAssembly.instantiate():
Import #0 module="env" function="puts" error:
function import requires a callable
```
_But we haven't compiled the LVGL Library to WebAssembly!_
Yep that's why LVGL Functions like `lv_label_create` are failing when the Web Browser loads our Zig WebAssembly...
```text
Uncaught (in promise) LinkError:
WebAssembly.instantiate():
Import #1 module="env" function="lv_label_create" error:
function import requires a callable
```
We need to compile the LVGL Library with `zig cc` and link it in...
# Compile LVGL to WebAssembly with Zig Compiler
_How to compile LVGL from C to WebAssembly with Zig Compiler?_
We'll use [`zig cc`](https://github.com/lupyuen/zig-bl602-nuttx#zig-compiler-as-drop-in-replacement-for-gcc), since Zig can compile C programs to WebAssembly.
In the previous section, we're missing the LVGL Function `lv_label_create` in our Zig WebAssembly Module.
`lv_label_create` is defined in this file...
```text
apps/lvgl/src/widgets/lv_label.c
```
According to `make --trace`, `lv_label.c` is compiled with...
```bash
## Compile LVGL in C
## TODO: Change "../../.." to your NuttX Project Directory
cd apps/graphics/lvgl
aarch64-none-elf-gcc \
-c \
-fno-common \
-Wall \
-Wstrict-prototypes \
-Wshadow \
-Wundef \
-Werror \
-Os \
-fno-strict-aliasing \
-fomit-frame-pointer \
-ffunction-sections \
-fdata-sections \
-g \
-march=armv8-a \
-mtune=cortex-a53 \
-isystem ../../../nuttx/include \
-D__NuttX__ \
-pipe \
-I ../../../apps/graphics/lvgl \
-I "../../../apps/include" \
-Wno-format \
-Wno-format-security \
-Wno-unused-variable \
"-I./lvgl/src/core" \
"-I./lvgl/src/draw" \
"-I./lvgl/src/draw/arm2d" \
"-I./lvgl/src/draw/nxp" \
"-I./lvgl/src/draw/nxp/pxp" \
"-I./lvgl/src/draw/nxp/vglite" \
"-I./lvgl/src/draw/sdl" \
"-I./lvgl/src/draw/stm32_dma2d" \
"-I./lvgl/src/draw/sw" \
"-I./lvgl/src/draw/swm341_dma2d" \
"-I./lvgl/src/font" \
"-I./lvgl/src/hal" \
"-I./lvgl/src/misc" \
"-I./lvgl/src/widgets" \
"-DLV_ASSERT_HANDLER=ASSERT(0);" \
./lvgl/src/widgets/lv_label.c \
-o lv_label.c.Users.Luppy.PinePhone.wip-nuttx.apps.graphics.lvgl.o
```
Let's use the Zig Compiler to compile `lv_label.c` from C to WebAssembly....
- Change `aarch64-none-elf-gcc` to `zig cc`
- Remove `-march`, `-mtune`
- Add the target `-target wasm32-freestanding`
- Add `-dynamic` and `-rdynamic`
- Add `-lc` (because we're calling C Standard Library)
- Add `-DFAR=` (because we won't need Far Pointers)
- Add `-DLV_MEM_CUSTOM=1` (because we're using `malloc` instead of LVGL's TLSF Allocator)
- Set the Default Font to Montserrat 20...
```text
-DLV_FONT_MONTSERRAT_14=1 \
-DLV_FONT_MONTSERRAT_20=1 \
-DLV_FONT_DEFAULT_MONTSERRAT_20=1 \
-DLV_USE_FONT_PLACEHOLDER=1 \
```
- Add `-DLV_USE_LOG=1` (to enable logging)
- Add `-DLV_LOG_LEVEL=LV_LOG_LEVEL_TRACE` (for detailed logging)
- For extra logging...
```text
-DLV_LOG_TRACE_OBJ_CREATE=1 \
-DLV_LOG_TRACE_TIMER=1 \
-DLV_LOG_TRACE_MEM=1 \
```
- Change `"-DLV_ASSERT_HANDLER..."` to...
```text
"-DLV_ASSERT_HANDLER={void lv_assert_handler(void); lv_assert_handler();}"
```
[(To handle Assertion Failures ourselves)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/bee0e8d8ab9eae3a8c7cea6c64cc7896a5678f53/lvglwasm.zig#L170-L190)
- Change the output to...
```text
-o ../../../pinephone-lvgl-zig/lv_label.o`
```
Like this...
```bash
## Compile LVGL from C to WebAssembly
## TODO: Change "../../.." to your NuttX Project Directory
cd apps/graphics/lvgl
zig cc \
-target wasm32-freestanding \
-dynamic \
-rdynamic \
-lc \
-DFAR= \
-DLV_MEM_CUSTOM=1 \
-DLV_FONT_MONTSERRAT_14=1 \
-DLV_FONT_MONTSERRAT_20=1 \
-DLV_FONT_DEFAULT_MONTSERRAT_20=1 \
-DLV_USE_FONT_PLACEHOLDER=1 \
-DLV_USE_LOG=1 \
-DLV_LOG_LEVEL=LV_LOG_LEVEL_TRACE \
-DLV_LOG_TRACE_OBJ_CREATE=1 \
-DLV_LOG_TRACE_TIMER=1 \
-DLV_LOG_TRACE_MEM=1 \
"-DLV_ASSERT_HANDLER={void lv_assert_handler(void); lv_assert_handler();}" \
-c \
-fno-common \
-Wall \
-Wstrict-prototypes \
-Wshadow \
-Wundef \
-Werror \
-Os \
-fno-strict-aliasing \
-fomit-frame-pointer \
-ffunction-sections \
-fdata-sections \
-g \
-isystem ../../../nuttx/include \
-D__NuttX__ \
-pipe \
-I ../../../apps/graphics/lvgl \
-I "../../../apps/include" \
-Wno-format \
-Wno-format-security \
-Wno-unused-variable \
"-I./lvgl/src/core" \
"-I./lvgl/src/draw" \
"-I./lvgl/src/draw/arm2d" \
"-I./lvgl/src/draw/nxp" \
"-I./lvgl/src/draw/nxp/pxp" \
"-I./lvgl/src/draw/nxp/vglite" \
"-I./lvgl/src/draw/sdl" \
"-I./lvgl/src/draw/stm32_dma2d" \
"-I./lvgl/src/draw/sw" \
"-I./lvgl/src/draw/swm341_dma2d" \
"-I./lvgl/src/font" \
"-I./lvgl/src/hal" \
"-I./lvgl/src/misc" \
"-I./lvgl/src/widgets" \
./lvgl/src/widgets/lv_label.c \
-o ../../../pinephone-lvgl-zig/lv_label.o
```
[(NuttX Build Files)](https://github.com/lupyuen/pinephone-lvgl-zig/releases/tag/nuttx-build-files)
This produces the Compiled WebAssembly `lv_label.o`.
_Will Zig Compiler let us link `lv_label.o` with our Zig LVGL App?_
Let's ask Zig Compiler to link `lv_label.o` with our Zig LVGL App [`lvglwasm.zig`](lvglwasm.zig)...
```bash
## Compile the Zig App for WebAssembly
## TODO: Change ".." to your NuttX Project Directory
zig build-lib \
--verbose-cimport \
-target wasm32-freestanding \
-dynamic \
-rdynamic \
-lc \
-DFAR= \
-DLV_MEM_CUSTOM=1 \
-DLV_FONT_MONTSERRAT_14=1 \
-DLV_FONT_MONTSERRAT_20=1 \
-DLV_FONT_DEFAULT_MONTSERRAT_20=1 \
-DLV_USE_FONT_PLACEHOLDER=1 \
-DLV_USE_LOG=1 \
-DLV_LOG_LEVEL=LV_LOG_LEVEL_TRACE \
-DLV_LOG_TRACE_OBJ_CREATE=1 \
-DLV_LOG_TRACE_TIMER=1 \
-DLV_LOG_TRACE_MEM=1 \
"-DLV_ASSERT_HANDLER={void lv_assert_handler(void); lv_assert_handler();}" \
-I . \
-isystem "../nuttx/include" \
-I "../apps/include" \
-I "../apps/graphics/lvgl" \
-I "../apps/graphics/lvgl/lvgl/src/core" \
-I "../apps/graphics/lvgl/lvgl/src/draw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/arm2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/pxp" \
-I "../apps/graphics/lvgl/lvgl/src/draw/nxp/vglite" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sdl" \
-I "../apps/graphics/lvgl/lvgl/src/draw/stm32_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/draw/sw" \
-I "../apps/graphics/lvgl/lvgl/src/draw/swm341_dma2d" \
-I "../apps/graphics/lvgl/lvgl/src/font" \
-I "../apps/graphics/lvgl/lvgl/src/hal" \
-I "../apps/graphics/lvgl/lvgl/src/misc" \
-I "../apps/graphics/lvgl/lvgl/src/widgets" \
lvglwasm.zig \
lv_label.o
```
[(Source)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/2e1c97e49e51b1cbbe0964a9512eba141d0dd09f/build.sh#L87-L191)
[(NuttX Build Files)](https://github.com/lupyuen/pinephone-lvgl-zig/releases/tag/nuttx-build-files)
Now we see this error in the Web Browser...
```text
Uncaught (in promise) LinkError:
WebAssembly.instantiate():
Import #0 module="env" function="lv_obj_clear_flag" error:
function import requires a callable
```
`lv_label_create` is no longer missing, because Zig Compiler has linked `lv_label.o` into our Zig LVGL App.
Yep Zig Compiler will happily link WebAssembly Object Files with our Zig App yay!
Now we need to compile `lv_obj_clear_flag` and the other LVGL Files from C to WebAssembly with Zig Compiler...
# Compile Entire LVGL Library to WebAssembly
When we track down `lv_obj_clear_flag` and the other Missing Functions (by sheer tenacity), we get this trail of LVGL Source Files that need to be compiled from C to WebAssembly...
```text
widgets/lv_label.c
core/lv_obj.c
misc/lv_mem.c
core/lv_event.c
core/lv_obj_style.c
core/lv_obj_pos.c
misc/lv_txt.c
draw/lv_draw_label.c
core/lv_obj_draw.c
misc/lv_area.c
core/lv_obj_scroll.c
font/lv_font.c
core/lv_obj_class.c
(And many more)
```
[(Based on LVGL 8.3.3)](https://github.com/lvgl/lvgl/tree/v8.3.3)
So we wrote a script to compile the above LVGL Source Files from C to WebAssembly with `zig cc`...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/2e1c97e49e51b1cbbe0964a9512eba141d0dd09f/build.sh#L7-L191
Which calls `compile_lvgl` to compile a single LVGL Source File from C to WebAssembly with `zig cc`...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/2e1c97e49e51b1cbbe0964a9512eba141d0dd09f/build.sh#L226-L288
_What happens after we compile the whole bunch of LVGL Source Files from C to WebAssembly?_
Now the Web Browser says that `strlen` is missing...
```text
Uncaught (in promise) LinkError:
WebAssembly.instantiate():
Import #0 module="env" function="strlen" error:
function import requires a callable
```
Let's fix `strlen`...
_Is it really OK to compile only the necessary LVGL Source Files? Instead of compiling ALL the LVGL Source Files?_
Be careful! We might miss out some symbols. Zig Compiler happily assumes that they are at WebAssembly Address 0...
- ["LVGL Screen Not Found"](https://github.com/lupyuen/pinephone-lvgl-zig#lvgl-screen-not-found)
And remember to compile the LVGL Fonts!
- ["LVGL Fonts"](https://github.com/lupyuen/pinephone-lvgl-zig#lvgl-fonts)
TODO: Disassemble the Compiled WebAssembly and look for other Undefined Variables at WebAssembly Address 0
# C Standard Library is Missing
_strlen is missing from our Zig WebAssembly..._
_But strlen should come from the C Standard Library! (musl)_
Not sure why `strlen` is missing, but we fixed it temporarily by copying from the Zig Library Source Code...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/e99593df6b46ced52f3f8ed644b9c6e455a9d682/lvglwasm.zig#L213-L265
This seems to be the [same problem mentioned here](https://github.com/andrewrk/lua-in-the-browser#status).
[(Referenced by this pull request)](https://github.com/ziglang/zig/pull/2512)
[(And this issue)](https://github.com/ziglang/zig/issues/5854)
TODO: Maybe because we didn't export `strlen` in our Main Program `lvglwasm.zig`?
TODO: Do we compile C Standard Library ourselves? From musl? Newlib? [wasi-libc](https://github.com/WebAssembly/wasi-libc)?
_What if we change the target to `wasm32-freestanding-musl`?_
Nope doesn't help, same problem.
_What if we use `zig build-exe` instead of `zig build-lib`?_
Sorry `zig build-exe` is meant for building WASI Executables. [(See this)](https://www.fermyon.com/wasm-languages/c-lang)
`zig build-exe` is not supposed to work for WebAssembly in the Web Browser. [(See this)](https://github.com/ziglang/zig/issues/1570#issuecomment-426370371)
# LVGL Porting Layer for WebAssembly
LVGL expects us to provide a `millis` function that returns the number of elapsed milliseconds...
```text
Uncaught (in promise) LinkError:
WebAssembly.instantiate():
Import #0 module="env" function="millis" error:
function import requires a callable
```
We implement `millis` ourselves for WebAssembly...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/bee0e8d8ab9eae3a8c7cea6c64cc7896a5678f53/lvglwasm.zig#L170-L190
TODO: Fix `millis`. How would it work in WebAssembly? Using a counter?
In the code above, we defined `lv_assert_handler` and `custom_logger` to handle Assertions and Logging in LVGL.
Let's talk about LVGL Logging...
# WebAssembly Logger for LVGL
Let's trace the LVGL Execution with a WebAssembly Logger.
(Remember: `printf` won't work in WebAssembly)
We set the Custom Logger for LVGL, so that we can print Log Messages to the JavaScript Console...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/f9dc7e1afba2f876c8397d753a79a9cb40b90b75/lvglwasm.zig#L32-L43
The Custom Logger is defined in our Zig Program...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/f9dc7e1afba2f876c8397d753a79a9cb40b90b75/lvglwasm.zig#L149-L152
`wasmlog` is our Zig Logger for WebAssembly: [wasmlog.zig](wasmlog.zig)
(Based on [daneelsan/zig-wasm-logger](https://github.com/daneelsan/zig-wasm-logger))
`jsConsoleLogWrite` and `jsConsoleLogFlush` are defined in our JavaScript...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/1ed4940d505e263727a36c362da54388be4cbca0/lvglwasm.js#L55-L66
`wasm.getString` also comes from our JavaScript...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/1ed4940d505e263727a36c362da54388be4cbca0/lvglwasm.js#L10-L27
Now we can see the LVGL Log Messages in the JavaScript Console yay! (Pic below)
```text
custom_logger: [Warn] (0.001, +1)
lv_disp_get_scr_act:
no display registered to get its active screen
(in lv_disp.c line #54)
```
Let's initialise the LVGL Display...
# Initialise LVGL Display
According to the LVGL Docs, this is how we initialise and operate LVGL...
1. Call `lv_init()`
1. Register the LVGL Display and LVGL Input Devices
1. Call `lv_tick_inc(x)` every x milliseconds in an interrupt to report the elapsed time to LVGL
(Not required, because LVGL calls `millis` to fetch the elapsed time)
1. Call `lv_timer_handler()` every few milliseconds to handle LVGL related tasks
[(Source)](https://docs.lvgl.io/8.3/porting/project.html#initialization)
To register the LVGL Display, we should do this...
- [Create LVGL Draw Buffer](https://docs.lvgl.io/8.3/porting/display.html#draw-buffer)
- [Register LVGL Display](https://docs.lvgl.io/8.3/porting/display.html#examples)
But we can't do this in Zig...
```zig
// Nope! lv_disp_drv_t is an Opaque Type
var disp_drv = c.lv_disp_drv_t{};
c.lv_disp_drv_init(&disp_drv);
```
Because `lv_disp_drv_t` is an Opaque Type.
[(`lv_disp_drv_t` contains Bit Fields, hence it's Opaque)](https://lupyuen.github.io/articles/lvgl#appendix-zig-opaque-types)
Thus we apply this workaround to create `lv_disp_drv_t` in C...
- ["Fix Opaque Types"](https://lupyuen.github.io/articles/lvgl#fix-opaque-types)
And we get this LVGL Display Interface for Zig: [display.c](display.c)
Finally this is how we initialise the LVGL Display in Zig WebAssembly...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/d584f43c6354f12bdc15bdb8632cdd3f6f5dc7ff/lvglwasm.zig#L38-L84
Now we handle LVGL Tasks...
# Handle LVGL Tasks
Earlier we talked about __handling LVGL Tasks__...
1. Call __lv_tick_inc(x)__ every __x__ milliseconds (in an Interrupt) to report the __Elapsed Time__ to LVGL
[(Not required, because LVGL calls __millis__ to fetch the Elapsed Time)](https://lupyuen.github.io/articles/lvgl3#lvgl-porting-layer-for-webassembly)
1. Call __lv_timer_handler__ every few milliseconds to handle __LVGL Tasks__
[(From the __LVGL Docs__)](https://docs.lvgl.io/8.3/porting/project.html#initialization)
This is how we call __lv_timer_handler__ in Zig: [lvglwasm.zig](https://github.com/lupyuen/pinephone-lvgl-zig/blob/main/lvglwasm.zig#L69-L85)
```zig
/// Main Function for our Zig LVGL App
pub export fn lv_demo_widgets() void {
// Omitted: Init LVGL Display
// Create the widgets for display
createWidgetsWrapped() catch |e| {
// In case of error, quit
std.log.err("createWidgetsWrapped failed: {}", .{e});
return;
};
// Handle LVGL Tasks
// TODO: Call this from Web Browser JavaScript,
// so that Web Browser won't block
var i: usize = 0;
while (i < 5) : (i += 1) {
_ = c.lv_timer_handler();
}
```
We're ready to render the LVGL Display in our HTML Page!
_Something doesn't look right..._
Yeah we should have called __lv_timer_handler__ from our JavaScript.
(Triggered by a JavaScript Timer or __requestAnimationFrame__)
But for our quick demo, this will do. For now!
# Render LVGL Display in Web Browser
Let's render the LVGL Display in the Web Browser! (Pic above)
(Based on [daneelsan/minimal-zig-wasm-canvas](https://github.com/daneelsan/minimal-zig-wasm-canvas))
LVGL renders the display pixels to `canvas_buffer`...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/5e4d661a7a9a962260d1f63c3b79a688037ed642/display.c#L95-L107
[(`init_disp_buf` is called by our Zig Program)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/d584f43c6354f12bdc15bdb8632cdd3f6f5dc7ff/lvglwasm.zig#L49-L63)
LVGL calls `flushDisplay` (in Zig) when the LVGL Display Canvas is ready to be rendered...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/d584f43c6354f12bdc15bdb8632cdd3f6f5dc7ff/lvglwasm.zig#L49-L63
`flushDisplay` (in Zig) calls `render` (in JavaScript) to render the LVGL Display Canvas...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/d584f43c6354f12bdc15bdb8632cdd3f6f5dc7ff/lvglwasm.zig#L86-L98
(Remember to call `lv_disp_flush_ready` or Web Browser will hang on reload)
`render` (in JavaScript) draws the LVGL Display to our HTML Canvas...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/1ed4940d505e263727a36c362da54388be4cbca0/lvglwasm.js#L29-L53
Which calls [`getCanvasBuffer`](https://github.com/lupyuen/pinephone-lvgl-zig/blob/d584f43c6354f12bdc15bdb8632cdd3f6f5dc7ff/lvglwasm.zig#L100-L104) (in Zig) and `get_canvas_buffer` (in C) to fetch the LVGL Canvas Buffer `canvas_buffer`...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/5e4d661a7a9a962260d1f63c3b79a688037ed642/display.c#L9-L29
Remember to set Direct Mode in the Display Driver!
https://github.com/lupyuen/pinephone-lvgl-zig/blob/86700c3453d91bc7d2fe0a46192fa41b7a24b6df/display.c#L94-L95
And the LVGL Display renders OK in our HTML Canvas yay! (Pic below)
# Handle LVGL Timer
To execute LVGL Tasks periodically, here's the proper way to handle the LVGL Timer in JavaScript...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/435435e01a4ffada2c93ecc3ec1af73a6220e7a0/feature-phone.js#L134-L150
`handleTimer` comes from our Zig LVGL App, it executes LVGL Tasks periodically...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/86700c3453d91bc7d2fe0a46192fa41b7a24b6df/feature-phone.zig#L213-L222
# Handle LVGL Input
Let's handle Mouse and Touch Input in LVGL!
We create an LVGL Button in our Zig LVGL App...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/86700c3453d91bc7d2fe0a46192fa41b7a24b6df/feature-phone.zig#L185-L196
`eventHandler` is our Zig Handler for Button Events...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/86700c3453d91bc7d2fe0a46192fa41b7a24b6df/feature-phone.zig#L198-L208
When our app starts, we register the LVGL Input Device...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/7eb99b6c4deca82310e42d30808944f25bb6255c/feature-phone.zig#L69-L75
[(We define `register_input` in C because `lv_indev_t` is an Opaque Type in Zig)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/main/display.c)
This tells LVGL to call `readInput` periodically to poll for input. (More about this below)
`indev_drv` is our LVGL Input Device Driver...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/7eb99b6c4deca82310e42d30808944f25bb6255c/feature-phone.zig#L287-L288
Now we handle Mouse and Touch Events in our JavaScript...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/435435e01a4ffada2c93ecc3ec1af73a6220e7a0/feature-phone.js#L77-L123
Which calls `notifyInput` in our Zig App to set the Input State and Input Coordinates...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/86700c3453d91bc7d2fe0a46192fa41b7a24b6df/feature-phone.zig#L224-L235
LVGL polls our `readInput` Zig Function periodically to read the Input State and Input Coordinates...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/86700c3453d91bc7d2fe0a46192fa41b7a24b6df/feature-phone.zig#L237-L253
[(We define `set_input_data` in C because `lv_indev_data_t` is an Opaque Type in Zig)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/main/display.c)
And the LVGL Button will respond correctly to Mouse and Touch Input in the Web Browser! (Pic below)
[(Try the LVGL Button Demo)](https://lupyuen.github.io/pinephone-lvgl-zig/feature-phone.html)
[(Watch the demo on YouTube)](https://youtube.com/shorts/J6ugzVyKC4U?feature=share)
[(See the log)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/e70b2df50fa562bec7e02f24191dbbb1e5a7553a/README.md#todo)
# Feature Phone UI
Read the article...
- ["NuttX RTOS for PinePhone: Feature Phone UI in LVGL, Zig and WebAssembly"](https://lupyuen.github.io/articles/lvgl4)
Let's create a Feature Phone UI for PinePhone on Apache NuttX RTOS!
We create 3 LVGL Containers for the Display Label, Call / Cancel Buttons and Digit Buttons...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/b8b12209dc99a7c477aaeaa475362e795f9b05fc/feature-phone.zig#L113-L136
We create the Display Label...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/b8b12209dc99a7c477aaeaa475362e795f9b05fc/feature-phone.zig#L139-L167
Then we create the Call and Cancel Buttons inside the Second Container...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/b8b12209dc99a7c477aaeaa475362e795f9b05fc/feature-phone.zig#L169-L184
Finally we create the Digit Buttons inside the Third Container...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/b8b12209dc99a7c477aaeaa475362e795f9b05fc/feature-phone.zig#L186-L201
[(Or use an LVGL Button Matrix)](https://docs.lvgl.io/8.3/widgets/core/btnmatrix.html)
When we test our Zig LVGL App in WebAssembly, we see this...
[(Try the Feature Phone Demo)](https://lupyuen.github.io/pinephone-lvgl-zig/feature-phone.html)
[(Watch the demo on YouTube)](https://www.youtube.com/shorts/iKa0bcSa22U)
[(See the log)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/1feb919e17018222dd3ebf79b206de97eb4cfbeb/README.md#output-log)
# Handle Buttons in Feature Phone UI
Now that we have rendered the Feature Phone UI in Zig and LVGL, let's wire up the Buttons.
Clicking any Button will call our Button Event Handler...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/9650c4bc2ef8065410ca4e643cde6ab6ae2d2f7d/feature-phone.zig#L189-L197
In our Button Event Handler, we identify the Button Clicked...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/9650c4bc2ef8065410ca4e643cde6ab6ae2d2f7d/feature-phone.zig#L205-L220
If it's a Digit Button, we append the Digit to the Phone Number...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/9650c4bc2ef8065410ca4e643cde6ab6ae2d2f7d/feature-phone.zig#L238-L242
If it's the Cancel Button, we erase the last digit of the Phone Number...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/9650c4bc2ef8065410ca4e643cde6ab6ae2d2f7d/feature-phone.zig#L232-L238
If it's the Call Button, we call PinePhone's LTE Modem to dial the Phone Number...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/9650c4bc2ef8065410ca4e643cde6ab6ae2d2f7d/feature-phone.zig#L222-L231
(Simulated for WebAssembly)
The buttons work OK on WebAssembly. (Pic below)
Let's run the Feature Phone UI on PinePhone and Apache NuttX RTOS!
[(Try the Feature Phone Demo)](https://lupyuen.github.io/pinephone-lvgl-zig/feature-phone.html)
[(Watch the demo on YouTube)](https://youtu.be/vBKhk5Q6rnE)
[(See the log)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/665847f513a44648b0d4ae602d6fcf7cc364a342/README.md#output-log)
# Feature Phone UI for Apache NuttX RTOS
_We created an LVGL Feature Phone UI for WebAssembly. Will it run on PinePhone?_
Let's refactor the LVGL Feature Phone UI, so that the same Zig Source File will run on BOTH WebAssembly and PinePhone! (With Apache NuttX RTOS)
We moved all the WebAssembly-Specific Functions to [`wasm.zig`](wasm.zig)...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/a0ead2b86fda34a23afee71411915ac8315537a0/wasm.zig#L19-L288
Our Zig LVGL App imports [`wasm.zig`](wasm.zig) only when compiling for WebAssembly...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/0aa3a1123ae64aaa75734456ce920de23ddc6aa2/feature-phone.zig#L15-L19
In our JavaScript, we call `initDisplay` (from [`wasm.zig`](wasm.zig)) to initialise the LVGL Display and LVGL Input for WebAssembly...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/521b7c7e06beaa53b1d6c8d88671650bddaae88e/feature-phone.js#L124-L153
_What about PinePhone on Apache NuttX RTOS?_
When compiling for NuttX, our Zig LVGL App imports [`nuttx.zig`](nuttx.zig)...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/0aa3a1123ae64aaa75734456ce920de23ddc6aa2/feature-phone.zig#L15-L19
Which defines the Custom Panic Handler and Custom Logger specific to NuttX...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/f2b768eabaa99ebb0acf5454823871ddf5675a59/nuttx.zig#L7-L70
We compile our Zig LVGL App for NuttX (using the exact same Zig Source File for WebAssembly)...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/4650bc8eb5f4d23fae03d17e82b511682e288f3d/build.sh#L403-L437
And our Feature Phone UI runs on PinePhone with NuttX yay! (Pic below)
The exact same Zig Source File runs on both WebAssembly and PinePhone, no changes needed! This is super helpful for creating LVGL Apps.
[(Watch the demo on YouTube)](https://www.youtube.com/shorts/tOUnj0XEP-Q)
[(See the PinePhone Log)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/07ec0cd87b7888ac20736a7472643ee5d4758096/README.md#pinephone-log)
# LVGL Fonts
Remember to compile the LVGL Fonts! Or nothing will be rendered...
```bash
## Compile LVGL Library from C to WebAssembly with Zig Compiler
compile_lvgl font/lv_font_montserrat_14.c lv_font_montserrat_14
compile_lvgl font/lv_font_montserrat_20.c lv_font_montserrat_20
## Compile the Zig LVGL App for WebAssembly
zig build-lib \
-DLV_FONT_MONTSERRAT_14=1 \
-DLV_FONT_MONTSERRAT_20=1 \
-DLV_FONT_DEFAULT_MONTSERRAT_20=1 \
-DLV_USE_FONT_PLACEHOLDER=1 \
...
lv_font_montserrat_14.o \
lv_font_montserrat_20.o \
```
[(Source)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/2e1c97e49e51b1cbbe0964a9512eba141d0dd09f/build.sh#L21-L191)
# LVGL Memory Allocation
_What happens if we omit `-DLV_MEM_CUSTOM=1`?_
By default, LVGL uses the [Two-Level Segregate Fit (TLSF) Allocator](http://www.gii.upv.es/tlsf/) for Heap Memory.
But TLSF Allocator fails in [`block_next`](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_tlsf.c#L453-L460)...
```text
main: start
loop: start
lv_demo_widgets: start
before lv_init
[Info] lv_init: begin (in lv_obj.c line #102)
[Trace] lv_mem_alloc: allocating 76 bytes (in lv_mem.c line #127)
[Trace] lv_mem_alloc: allocated at 0x1a700 (in lv_mem.c line #160)
[Trace] lv_mem_alloc: allocating 28 bytes (in lv_mem.c line #127)
[Trace] lv_mem_alloc: allocated at 0x1a750 (in lv_mem.c line #160)
[Warn] lv_init: Log level is set to 'Trace' which makes LVGL much slower (in lv_obj.c line #176)
[Trace] lv_mem_realloc: reallocating 0x14 with 8 size (in lv_mem.c line #196)
[Error] block_next: Asserted at expression: !block_is_last(block) (in lv_tlsf.c line #459)
004a5b4a:0x29ab2 Uncaught (in promise) RuntimeError: unreachable
at std.builtin.default_panic (004a5b4a:0x29ab2)
at lv_assert_handler (004a5b4a:0x2ac6c)
at block_next (004a5b4a:0xd5b3)
at lv_tlsf_realloc (004a5b4a:0xe226)
at lv_mem_realloc (004a5b4a:0x20f1)
at lv_layout_register (004a5b4a:0x75d8)
at lv_flex_init (004a5b4a:0x16afe)
at lv_extra_init (004a5b4a:0x16ae5)
at lv_init (004a5b4a:0x3f28)
at lv_demo_widgets (004a5b4a:0x29bb9)
```
Thus we set `-DLV_MEM_CUSTOM=1` to use `malloc` instead of LVGL's TLSF Allocator.
([`block_next`](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_tlsf.c#L453-L460) calls [`offset_to_block`](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_tlsf.c#L440-L444), which calls [`tlsf_cast`](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_tlsf.c#L274). Maybe the Pointer Cast doesn't work for Clang WebAssembly?)
_But Zig doesn't support `malloc` for WebAssembly!_
We used Zig's FixedBufferAllocator...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/43fa982d38a7ae8f931c171a80b006a9faa95b58/lvglwasm.zig#L38-L44
To implement `malloc` ourselves...
https://github.com/lupyuen/pinephone-lvgl-zig/blob/43fa982d38a7ae8f931c171a80b006a9faa95b58/lvglwasm.zig#L195-L237
[(Remember to copy the old memory in `realloc`!)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/aade32dd70286866676b2d9728970c6b3cca9489/README.md#todo)
[(If we ever remove `-DLV_MEM_CUSTOM=1`, remember to set `-DLV_MEM_SIZE=1000000`)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/aa080fb2ce55f9959cce2b6fff7e5fd5c9907cd6/README.md#lvgl-memory-allocation)
TODO: How to disassemble Compiled WebAssembly with cross-reference to Source Code? Like `objdump --source`? See [wabt](https://github.com/WebAssembly/wabt) and [binaryen](https://github.com/WebAssembly/binaryen)
# LVGL Screen Not Found
_Why does LVGL say "no screen found" in [lv_obj_get_disp](https://github.com/lvgl/lvgl/blob/v8.3.3/src/core/lv_obj_tree.c#L270-L289)?_
That's because the Display Linked List `_lv_disp_ll` is allocated by `LV_ITERATE_ROOTS` in [_lv_gc_clear_roots](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_gc.c#L42)...
And we forgot to compile [_lv_gc_clear_roots](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_gc.c#L42) in [lv_gc.c](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_gc.c#L42). Duh!
(Zig Compiler assumes that missing variables like `_lv_disp_ll` are at WebAssembly Address 0)
After compiling [_lv_gc_clear_roots](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_gc.c#L42) and [lv_gc.c](https://github.com/lvgl/lvgl/blob/v8.3.3/src/misc/lv_gc.c#L42), the "no screen found" error below no longer appears.
TODO: Disassemble the Compiled WebAssembly and look for other Undefined Variables at WebAssembly Address 0
```text
[Info] lv_init: begin (in lv_obj.c line #102)
[Trace] lv_init: finished (in lv_obj.c line #183)
before lv_disp_drv_register
[Warn] lv_obj_get_disp: No screen found (in lv_obj_tree.c line #290)
[Info] lv_obj_create: begin (in lv_obj.c line #206)
[Trace] lv_obj_class_create_obj: Creating object with 0x12014 class on 0 parent (in lv_obj_class.c line #45)
[Warn] lv_obj_get_disp: No screen found (in lv_obj_tree.c line #290)
```
[(See the Complete Log)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/9610bb5209a072fc5950cf0559b1274d53dd8b8b/README.md#lvgl-screen-not-found)
# Zig with Rancher Desktop
The [Official Zig Download for macOS](https://ziglang.org/download/) no longer runs on my 10-year-old MacBook Pro that's stuck on macOS 10.15. 😢
To run the latest version of Zig Compiler, I use Rancher Desktop and VSCode Remote Containers...
- [VSCode Remote Containers on Rancher Desktop](https://docs.rancherdesktop.io/how-to-guides/vs-code-remote-containers)
Here's how...
1. Install [Rancher Desktop](https://rancherdesktop.io/)
1. In Rancher Desktop, click "Settings"...
Set "Container Engine" to "dockerd (moby)"
Under "Kubernetes", uncheck "Enable Kubernetes"
(To reduce CPU Utilisation)
1. Restart VSCode to use the new PATH
Install the VSCode Docker Extension
In VSCode, click the Docker icon in the Left Bar
1. Under "Containers", click "+" and "New Dev Container"
Select "Alpine"
1. In a while, we'll see VSCode running inside the Alpine Linux Container
We have finally Linux on macOS!
```text
$ uname -a
Linux bc0c45900671 5.15.96-0-virt #1-Alpine SMP Sun, 26 Feb 2023 15:14:12 +0000 x86_64 GNU/Linux
```
1. Now we can download and run the latest and greatest Zig Compiler for Linux x64 [(from here)](https://ziglang.org/download/)
```bash
wget https://ziglang.org/builds/zig-linux-x86_64-0.11.0-dev.3283+7cb3a6750.tar.xz
tar -xvf zig-linux-x86_64-0.11.0-dev.3283+7cb3a6750.tar.xz
zig-linux-x86_64-0.11.0-dev.3283+7cb3a6750/zig version
```
1. To install the NuttX Toolchain on Alpine Linux...
["Build Apache NuttX RTOS on Alpine Linux"](https://gist.github.com/lupyuen/880caa0547378028243b8cc5cfdc50a8)
1. To forward Network Ports, click the "Ports" tab beside "Terminal"
To configure other features in the Alpine Linux Container, edit the file `.devcontainer/devcontainer.json`
# Zig Version
(Here's what happens if we don't run Zig in a Container... We're stuck with an older version of Zig)
_Which version of Zig are we using?_
We're using an older version: `0.10.0-dev.2351+b64a1d5ab`
Sadly Zig 0.10.1 (and later) won't run on my 10-year-old MacBook Pro that's stuck on macOS 10.15 😢
```text
→ # Compile the Zig App for PinePhone
# (armv8-a with cortex-a53)
# TODO: Change ".." to your NuttX Project Directory
zig build-obj \
--verbose-cimport \
-target aarch64-freestanding-none \
-mcpu cortex_a53 \
-isystem "../nuttx/include" \
-I "../apps/include" \
lvgltest.zig
dyld: lazy symbol binding faileddyld: lazy symbol binding faileddyld: lazy symbol binding failed: Symbol not found: ___ulock_wai: Symbol not found: ___ulock_wait2
Referenced from: /Users/Lupt2
Referenced from: /Users/Lupdyld: lazy symbol binding failedpy/zig-macos-x86_64-0.10.1/zig (py/zig-macos-x86_64-0.10.1/zig (dyld: lazy symbol binding failedwhich was built for Mac OS X 11.: Symbol not found: ___ulock_wai: Symbol not found: ___ulock_waiwhich was built for Mac OS X 11.7)
Expected in: /usr/lib/libSy: Symbol not found: ___ulock_wai7)
Expected in: /usr/lib/libSystem.B.dylib
stem.B.dylib
t2
Referenced from: /Users/Lupt2
Referenced from: /Users/Lupt2
Referenced from: /Users/Luppy/zig-macos-x86_64-0.10.1/zig (py/zig-macos-x86_64-0.10.1/zig (py/zig-macos-x86_64-0.10.1/zig (which was built for Mac OS X 11.which was built for Mac OS X 11.which was built for Mac OS X 11.7)
Expected in: /usr/lib/libSy7)
Expected in: /usr/lib/libSydyld: Symbol not found: ___ulock7)
Expected in: /usr/lib/libSystem.B.dylib
stem.B.dylib
_wait2
Referenced from: /Usersstem.B.dylib
/Luppy/zig-macos-x86_64-0.10.1/zdyld: Symbol not found: ___ulockig (which was built for Mac OS X_wait2
Referenced from: /Users 11.7)
Expected in: /usr/lib/ldyld: Symbol not found: ___ulockdyld: Symbol not found: ___ulock/Luppy/zig-macos-x86_64-0.10.1/zibSystem.B.dylib
_wait2
Referenced from: /Usersig (which was built for Mac OS X_wait2
Referenced from: /Users/Luppy/zig-macos-x86_64-0.10.1/z 11.7)
Expected in: /usr/lib/l/Luppy/zig-macos-x86_64-0.10.1/zig (which was built for Mac OS XibSystem.B.dylib
ig (which was built for Mac OS X 11.7)
Expected in: /usr/lib/l 11.7)
Expected in: /usr/lib/libSystem.B.dylib
ibSystem.B.dylib
dyld: Symbol not found: ___ulockdyld: lazy symbol binding faileddyld: lazy symbol binding failed[1] 11157 abort zig build-obj --verbose-cimport -target aarch64-freestanding-none -mcpu -I
```
I tried building Zig from source, but it didn't work either...
# Build Zig from Source
The [Official Zig Download for macOS](https://ziglang.org/download/) no longer runs on my 10-year-old MacBook Pro that's stuck on macOS 10.15. (See the previous section)
So I tried building Zig from Source according to these instructions...
- [Building Zig from Source](https://github.com/ziglang/zig/wiki/Building-Zig-From-Source)
Here's what I did...
```bash
brew install llvm
git clone --recursive https://github.com/ziglang/zig
cd zig
mkdir build
cd build
cmake .. -DZIG_STATIC_LLVM=ON -DCMAKE_PREFIX_PATH="$(brew --prefix llvm);$(brew --prefix zstd)"
make install
```
`brew install llvm` failed...
[(Previously here)](https://github.com/lupyuen/pinephone-lvgl-zig/blob/7c6af9cd59788b67b18b85966b78f5b9aaadb10e/README.md#build-zig-from-source)
[__UPDATE:__ This has been fixed](https://github.com/lupyuen/pinephone-lvgl-zig/commit/b3e395839047180b67502dbf81a358a1d604b8a9)
So I tried building LLVM from source [(from here)](https://github.com/ziglang/zig/wiki/How-to-build-LLVM,-libclang,-and-liblld-from-source#posix)...
```bash
cd ~/Downloads
git clone --depth 1 --branch release/16.x https://github.com/llvm/llvm-project llvm-project-16
cd llvm-project-16
git checkout release/16.x
mkdir build-release
cd build-release
cmake ../llvm \
-DCMAKE_INSTALL_PREFIX=$HOME/local/llvm16-release \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_ENABLE_PROJECTS="lld;clang" \
-DLLVM_ENABLE_LIBXML2=OFF \
-DLLVM_ENABLE_TERMINFO=OFF \
-DLLVM_ENABLE_LIBEDIT=OFF \
-DLLVM_ENABLE_ASSERTIONS=ON \
-DLLVM_PARALLEL_LINK_JOBS=1 \
-G Ninja
ninja install
```
But LLVM fails to build...
```text
→ ninja install
[1908/4827] Building CXX object lib/Target/AMDGPU/AsmParser/CMakeFiles/LLVMAMDGPUAsmParser.dir/AMDGPUAsmParser.cpp.o
FAILED: lib/Target/AMDGPU/AsmParser/CMakeFiles/LLVMAMDGPUAsmParser.dir/AMDGPUAsmParser.cpp.o
/Applications/Xcode.app/Contents/Developer/usr/bin/g++ -DGTEST_HAS_RTTI=0 -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/Users/Luppy/llvm-project-16/build-release/lib/Target/AMDGPU/AsmParser -I/Users/Luppy/llvm-project-16/llvm/lib/Target/AMDGPU/AsmParser -I/Users/Luppy/llvm-project-16/llvm/lib/Target/AMDGPU -I/Users/Luppy/llvm-project-16/build-release/lib/Target/AMDGPU -I/Users/Luppy/llvm-project-16/build-release/include -I/Users/Luppy/llvm-project-16/llvm/include -isystem /usr/local/include -fPIC -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wstring-conversion -Wctad-maybe-unsupported -fdiagnostics-color -O3 -DNDEBUG -std=c++17 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -fno-exceptions -fno-rtti -UNDEBUG -MD -MT lib/Target/AMDGPU/AsmParser/CMakeFiles/LLVMAMDGPUAsmParser.dir/AMDGPUAsmParser.cpp.o -MF lib/Target/AMDGPU/AsmParser/CMakeFiles/LLVMAMDGPUAsmParser.dir/AMDGPUAsmParser.cpp.o.d -o lib/Target/AMDGPU/AsmParser/CMakeFiles/LLVMAMDGPUAsmParser.dir/AMDGPUAsmParser.cpp.o -c /Users/Luppy/llvm-project-16/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp
/Users/Luppy/llvm-project-16/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp:5490:13: error: no viable constructor or deduction guide for deduction of template arguments of 'tuple'
? std::tuple(HSAMD::V3::AssemblerDirectiveBegin,
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:625:5: note: candidate template ignored: requirement '__lazy_and, std::__1::__lazy_all<> >::value' was not satisfied [with _Tp = <>, _AllocArgT = const char *, _Alloc = char [21], _Dummy = true]
tuple(_AllocArgT, _Alloc const& __a)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:641:5: note: candidate template ignored: requirement '_CheckArgsConstructor::__enable_implicit()' was not satisfied [with _Tp = , _Dummy = true]
tuple(const _Tp& ... __t) _NOEXCEPT_((__all::value...>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:659:14: note: candidate template ignored: requirement '_CheckArgsConstructor::__enable_explicit()' was not satisfied [with _Tp = , _Dummy = true]
explicit tuple(const _Tp& ... __t) _NOEXCEPT_((__all::value...>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:677:7: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [21], _Dummy = true]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:697:7: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [21], _Dummy = true]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:723:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Up = ]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(_Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:756:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Up = ]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(_Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:783:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [21], _Up = <>]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:803:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [21], _Up = <>]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:612:23: note: candidate function template not viable: requires 0 arguments, but 2 were provided
_LIBCPP_CONSTEXPR tuple()
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:615:5: note: candidate function template not viable: requires 1 argument, but 2 were provided
tuple(tuple const&) = default;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:616:5: note: candidate function template not viable: requires 1 argument, but 2 were provided
tuple(tuple&&) = default;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:822:9: note: candidate function template not viable: requires single argument '__t', but 2 arguments were provided
tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:837:9: note: candidate function template not viable: requires single argument '__t', but 2 arguments were provided
tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:850:9: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:864:9: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:469:28: note: candidate function template not viable: requires 1 argument, but 2 were provided
class _LIBCPP_TEMPLATE_VIS tuple
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:932:1: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc&, tuple<_Args...> const&) -> tuple<_Args...>;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:934:1: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc&, tuple<_Args...>&&) -> tuple<_Args...>;
^
/Users/Luppy/llvm-project-16/llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp:5492:13: error: no viable constructor or deduction guide for deduction of template arguments of 'tuple'
: std::tuple(HSAMD::AssemblerDirectiveBegin,
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:625:5: note: candidate template ignored: requirement '__lazy_and, std::__1::__lazy_all<> >::value' was not satisfied [with _Tp = <>, _AllocArgT = const char *, _Alloc = char [29], _Dummy = true]
tuple(_AllocArgT, _Alloc const& __a)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:641:5: note: candidate template ignored: requirement '_CheckArgsConstructor::__enable_implicit()' was not satisfied [with _Tp = , _Dummy = true]
tuple(const _Tp& ... __t) _NOEXCEPT_((__all::value...>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:659:14: note: candidate template ignored: requirement '_CheckArgsConstructor::__enable_explicit()' was not satisfied [with _Tp = , _Dummy = true]
explicit tuple(const _Tp& ... __t) _NOEXCEPT_((__all::value...>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:677:7: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [29], _Dummy = true]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:697:7: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [29], _Dummy = true]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:723:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Up = ]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(_Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:756:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Up = ]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(_Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:783:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [29], _Up = <>]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:803:9: note: candidate template ignored: substitution failure [with _Tp = <>, _Alloc = char [29], _Up = <>]: cannot reference member of primary template because deduced class template specialization 'tuple<>' is an explicit specialization
tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:612:23: note: candidate function template not viable: requires 0 arguments, but 2 were provided
_LIBCPP_CONSTEXPR tuple()
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:615:5: note: candidate function template not viable: requires 1 argument, but 2 were provided
tuple(tuple const&) = default;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:616:5: note: candidate function template not viable: requires 1 argument, but 2 were provided
tuple(tuple&&) = default;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:822:9: note: candidate function template not viable: requires single argument '__t', but 2 arguments were provided
tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:837:9: note: candidate function template not viable: requires single argument '__t', but 2 arguments were provided
tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:850:9: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:864:9: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:469:28: note: candidate function template not viable: requires 1 argument, but 2 were provided
class _LIBCPP_TEMPLATE_VIS tuple
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:932:1: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc&, tuple<_Args...> const&) -> tuple<_Args...>;
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/tuple:934:1: note: candidate function template not viable: requires 3 arguments, but 2 were provided
tuple(allocator_arg_t, const _Alloc&, tuple<_Args...>&&) -> tuple<_Args...>;
^
2 errors generated.
[1917/4827] Building CXX object lib/Target/AMDGPU/Disassembler/CMakeFiles/LLVMAMDGPUDisassembler.dir/AMDGPUDisassembler.cpp.o
ninja: build stopped: subcommand failed.
```
So I can't build Zig from source on my 10-year-old MacBook Pro 😢
# Output Log
Here's the log from the JavaScript Console...
```text
main: start
lv_demo_widgets: start
[Info] lv_init: begin (in lv_obj.c line #102)
[Warn] lv_init: Log level is set to 'Trace' which makes LVGL much slower (in lv_obj.c line #176)
[Trace] lv_init: finished (in lv_obj.c line #183)
[Info] lv_obj_create: begin (in lv_obj.c line #206)
[Trace] lv_obj_class_create_obj: Creating object with 0x1773c class on 0 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating a screen (in lv_obj_class.c line #55)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Info] lv_obj_create: begin (in lv_obj.c line #206)
[Trace] lv_obj_class_create_obj: Creating object with 0x1773c class on 0 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating a screen (in lv_obj_class.c line #55)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Info] lv_obj_create: begin (in lv_obj.c line #206)
[Trace] lv_obj_class_create_obj: Creating object with 0x1773c class on 0 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating a screen (in lv_obj_class.c line #55)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
createWidgets: start
[Info] lv_obj_create: begin (in lv_obj.c line #206)
[Trace] lv_obj_class_create_obj: Creating object with 0x1773c class on 0x39e320 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Info] lv_obj_create: begin (in lv_obj.c line #206)
[Trace] lv_obj_class_create_obj: Creating object with 0x1773c class on 0x39e320 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] lv_obj_create: begin (in lv_obj.c line #206)
[Trace] lv_obj_class_create_obj: Creating object with 0x1773c class on 0x39e320 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39e57a parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e692 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39e9bc parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e692 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39ec98 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39ef5e parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39f237 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39f4f8 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39f7bd parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39fa86 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x39fd53 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x3a0024 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x3a02f9 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x3a05d2 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x3a08af parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x3a0b90 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
[Info] lv_btn_create: begin (in lv_btn.c line #51)
[Trace] lv_obj_class_create_obj: Creating object with 0x17d4c class on 0x39e792 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_btn_constructor: begin (in lv_btn.c line #64)
[Trace] lv_btn_constructor: finished (in lv_btn.c line #69)
[Info] lv_label_create: begin (in lv_label.c line #75)
[Trace] lv_obj_class_create_obj: Creating object with 0x17720 class on 0x3a0e75 parent (in lv_obj_class.c line #45)
[Trace] lv_obj_class_create_obj: creating normal object (in lv_obj_class.c line #82)
[Trace] lv_obj_constructor: begin (in lv_obj.c line #403)
[Trace] lv_obj_constructor: finished (in lv_obj.c line #428)
[Trace] lv_label_constructor: begin (in lv_label.c line #691)
[Trace] lv_label_constructor: finished (in lv_label.c line #721)
createWidgets: end
lv_demo_widgets: end
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Info] flex_update: update 0x39e57a container (in lv_flex.c line #211)
[Info] flex_update: update 0x39e692 container (in lv_flex.c line #211)
[Info] flex_update: update 0x39e792 container (in lv_flex.c line #211)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Info] flex_update: update 0x39e57a container (in lv_flex.c line #211)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
get_canvas_buffer: 803944 non-empty pixels
main: end
{mousedown: {…}}
readInput: state=1, x=162, y=491
[Info] (4.322, +4056) indev_proc_press: pressed at x:162 y:491 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (4.355, +33) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
{mouseup: {…}}
[Info] (4.373, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Info] (4.374, +1) flex_update: update 0x39e57a container (in lv_flex.c line #211)
[Trace] (4.375, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
[Info] (4.376, +1) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (4.377, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
readInput: state=0, x=162, y=491
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
2get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=334, y=494
[Info] (4.689, +312) indev_proc_press: pressed at x:334 y:494 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (4.721, +32) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (4.740, +19) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (4.741, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=334, y=494
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=570, y=493
[Info] (5.108, +367) indev_proc_press: pressed at x:570 y:493 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (5.158, +50) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (5.162, +4) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (5.163, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=570, y=493
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
get_canvas_buffer: 803940 non-empty pixels
get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=186, y=669
[Info] (6.075, +912) indev_proc_press: pressed at x:186 y:669 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (6.106, +31) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (6.124, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (6.125, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=186, y=669
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
get_canvas_buffer: 803940 non-empty pixels
get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=336, y=643
[Info] (6.474, +349) indev_proc_press: pressed at x:336 y:643 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (6.509, +35) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (6.513, +4) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (6.514, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=336, y=643
get_canvas_buffer: 803952 non-empty pixels
get_canvas_buffer: 803944 non-empty pixels
get_canvas_buffer: 803940 non-empty pixels
get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=519, y=631
[Info] (6.941, +427) indev_proc_press: pressed at x:519 y:631 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (6.975, +34) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (6.979, +4) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (6.980, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=519, y=631
get_canvas_buffer: 803952 non-empty pixels
get_canvas_buffer: 803698 non-empty pixels
get_canvas_buffer: 803956 non-empty pixels
2get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=559, y=282
[Info] (7.725, +745) indev_proc_press: pressed at x:559 y:282 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (7.757, +32) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (7.775, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (7.776, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
get_canvas_buffer: 803956 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=559, y=282
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=559, y=282
[Info] (8.159, +383) indev_proc_press: pressed at x:559 y:282 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (8.191, +32) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (8.209, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (8.210, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
get_canvas_buffer: 803956 non-empty pixels
readInput: state=0, x=559, y=282
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=559, y=282
[Info] (8.493, +283) indev_proc_press: pressed at x:559 y:282 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (8.525, +32) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (8.543, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (8.544, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
get_canvas_buffer: 803956 non-empty pixels
readInput: state=0, x=559, y=282
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=155, y=643
[Info] (9.376, +832) indev_proc_press: pressed at x:155 y:643 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (9.408, +32) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (9.427, +19) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (9.428, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
get_canvas_buffer: 803956 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=155, y=643
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=327, y=640
[Info] (9.844, +416) indev_proc_press: pressed at x:327 y:640 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (9.876, +32) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (9.894, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (9.895, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=327, y=640
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=554, y=637
[Info] (10.362, +467) indev_proc_press: pressed at x:554 y:637 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (10.392, +30) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (10.411, +19) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (10.412, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
get_canvas_buffer: 803956 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=554, y=637
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=197, y=768
[Info] (11.029, +617) indev_proc_press: pressed at x:197 y:768 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (11.059, +30) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (11.081, +22) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (11.082, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
get_canvas_buffer: 803956 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=197, y=768
get_canvas_buffer: 803952 non-empty pixels
get_canvas_buffer: 803940 non-empty pixels
get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=362, y=766
[Info] (11.428, +346) indev_proc_press: pressed at x:362 y:766 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (11.460, +32) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (11.478, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (11.479, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=362, y=766
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=593, y=769
[Info] (11.895, +416) indev_proc_press: pressed at x:593 y:769 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (11.928, +33) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (11.945, +17) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (11.946, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=593, y=769
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=368, y=915
[Info] (12.629, +683) indev_proc_press: pressed at x:368 y:915 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (12.662, +33) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
[Info] (12.680, +18) lv_obj_update_layout: Layout update begin (in lv_obj_pos.c line #314)
[Trace] (12.681, +1) lv_obj_update_layout: Layout update end (in lv_obj_pos.c line #317)
2get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
readInput: state=0, x=368, y=915
get_canvas_buffer: 803956 non-empty pixels
get_canvas_buffer: 803952 non-empty pixels
get_canvas_buffer: 803940 non-empty pixels
get_canvas_buffer: 803944 non-empty pixels
{mousedown: {…}}
readInput: state=1, x=219, y=274
[Info] (13.328, +647) indev_proc_press: pressed at x:219 y:274 (in lv_indev.c line #819)
get_canvas_buffer: 803944 non-empty pixels
[Info] (13.361, +33) indev_proc_release: released (in lv_indev.c line #969)
eventHandler: clicked
Call +1234567890
Running in WebAssembly, simulate the Phone Call
get_canvas_buffer: 803944 non-empty pixels
{mouseup: {…}}
get_canvas_buffer: 803956 non-empty pixels
readInput: state=0, x=219, y=274
get_canvas_buffer: 803952 non-empty pixels
3get_canvas_buffer: 803944 non-empty pixels
```
# PinePhone Log
Here's the log from PinePhone on Apache NuttX RTOS...
```text
DRAM: 2048 MiB
Trying to boot from MMC1
NOTICE: BL31: v2.2(release):v2.2-904-gf9ea3a629
NOTICE: BL31: Built : 15:32:12, Apr 9 2020
NOTICE: BL31: Detected Allwinner A64/H64/R18 SoC (1689)
NOTICE: BL31: Found U-Boot DTB at 0x4064410, model: PinePhone
NOTICE: PSCI: System suspend is unavailable
U-Boot 2020.07 (Nov 08 2020 - 00:15:12 +0100)
DRAM: 2 GiB
MMC: Device 'mmc@1c11000': seq 1 is in use by 'mmc@1c10000'
mmc@1c0f000: 0, mmc@1c10000: 2, mmc@1c11000: 1
Loading Environment from FAT... *** Warning - bad CRC, using default environment
starting USB...
No working controllers found
Hit any key to stop autoboot: 0
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
Found U-Boot script /boot.scr
653 bytes read in 3 ms (211.9 KiB/s)
## Executing script at 4fc00000
gpio: pin 114 (gpio 114) value is 1
276622 bytes read in 16 ms (16.5 MiB/s)
Uncompressed size: 10387456 = 0x9E8000
36162 bytes read in 4 ms (8.6 MiB/s)
1078500 bytes read in 50 ms (20.6 MiB/s)
## Flattened Device Tree blob at 4fa00000
Booting using the fdt blob at 0x4fa00000
Loading Ramdisk to 49ef8000, end 49fff4e4 ... OK
Loading Device Tree to 0000000049eec000, end 0000000049ef7d41 ... OK
Starting kernel ...
nsh: mkfatfs: command not found
NuttShell (NSH) NuttX-12.0.3
nsh> lvgldemo
lv_demo_widgets: start
createWidgets: start
createWidgets: end
lv_demo_widgets: end
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
eventHandler: clicked
Call +1234567890
Running on PinePhone, make an actual Phone Call
```