Remove TactilityC and Firmware subprojects (#638)

- Removed TactilityC, moved its symbols to existing modules and several new ones (pthread-module, c-symbols-module, cpp-symbols-module, posix-symbols-module, freertos-module).
- Removed Firmware subproject and moved main() into Tactility subproject.
- Strengthened application archive, path, version, stack-size, and device validation.
- Moved symbol resolution for elf_loader to app-esp32-module.
- Improved `struct Module` declarations and made module and symbol definitions in modules more consistent.
- Removed old http download code from Tactility subproject.
- Rename app-module's source files for consistency.
- Add missing pthread symbols.
- Kernel module symbols are now resolvable on all platforms.

TactilityKernel/include/tactility/module.h

@@ -13,6 +13,9 @@
 #endif
 
 #define DEFINE_MODULE_SYMBOL(symbol) { #symbol, (void*)&symbol }
+/** For an overloaded symbol (e.g. libc++/libstdc++'s float/double/long double math overloads),
+ * where a bare `&symbol` is ambiguous - `type` picks the overload to take the address of. */
+#define DEFINE_MODULE_SYMBOL_SIGNATURE(symbol, type) { #symbol, (void*)(type)&symbol }
 
 #ifdef __cplusplus
 extern "C" {

TactilityKernel/source/drivers/gpio_backlight.cpp

@@ -125,7 +125,7 @@ static error_t stop(Device* device) {
 
 // endregion
 
-extern Module root_module;
+extern Module kernel_module;
 
 Driver gpio_backlight_driver = {
     .name = "gpio_backlight",
@@ -134,7 +134,7 @@ Driver gpio_backlight_driver = {
     .stop_device = stop,
     .api = &GPIO_BACKLIGHT_API,
     .device_type = &BACKLIGHT_TYPE,
-    .owner = &root_module,
+    .owner = &kernel_module,
     .internal = nullptr
 };
 

TactilityKernel/source/drivers/gpio_hog.cpp

@@ -57,7 +57,7 @@ static error_t stop(Device* device) {
     return ERROR_NONE;
 }
 
-extern Module root_module;
+extern Module kernel_module;
 
 Driver gpio_hog_driver = {
     .name = "gpio_hog",
@@ -66,6 +66,6 @@ Driver gpio_hog_driver = {
     .stop_device = stop,
     .api = nullptr,
     .device_type = &GPIO_HOG_TYPE,
-    .owner = &root_module,
+    .owner = &kernel_module,
     .internal = nullptr
 };

TactilityKernel/source/drivers/pwm_backlight.cpp

@@ -126,7 +126,7 @@ static error_t stop(Device* device) {
 
 // endregion
 
-extern Module root_module;
+extern Module kernel_module;
 
 Driver pwm_backlight_driver = {
     .name = "pwm_backlight",
@@ -135,7 +135,7 @@ Driver pwm_backlight_driver = {
     .stop_device = stop,
     .api = &PWM_BACKLIGHT_API,
     .device_type = &BACKLIGHT_TYPE,
-    .owner = &root_module,
+    .owner = &kernel_module,
     .internal = nullptr
 };
 

TactilityKernel/source/drivers/rgb_led_gpio.cpp

@@ -146,7 +146,7 @@ static error_t stop(Device* device) {
 
 // endregion
 
-extern Module root_module;
+extern Module kernel_module;
 
 Driver rgb_led_gpio_driver = {
     .name = "rgb_led_gpio",
@@ -155,7 +155,7 @@ Driver rgb_led_gpio_driver = {
     .stop_device = stop,
     .api = &RGB_LED_GPIO_API,
     .device_type = &RGB_LED_TYPE,
-    .owner = &root_module,
+    .owner = &kernel_module,
     .internal = nullptr
 };
 

TactilityKernel/source/drivers/rgb_led_pwm.cpp

@@ -141,7 +141,7 @@ static error_t stop(Device* device) {
 
 // endregion
 
-extern Module root_module;
+extern Module kernel_module;
 
 Driver rgb_led_pwm_driver = {
     .name = "rgb_led_pwm",
@@ -150,7 +150,7 @@ Driver rgb_led_pwm_driver = {
     .stop_device = stop,
     .api = &RGB_LED_PWM_API,
     .device_type = &RGB_LED_TYPE,
-    .owner = &root_module,
+    .owner = &kernel_module,
     .internal = nullptr
 };
 

TactilityKernel/source/kernel_init.cpp

@@ -11,42 +11,44 @@ extern "C" {
 
 extern const ModuleSymbol KERNEL_SYMBOLS[];
 
-static error_t start() {
-    extern Driver root_driver;
-    if (driver_construct_add(&root_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    extern Driver battery_sense_driver;
-    if (driver_construct_add(&battery_sense_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    extern Driver battery_sense_power_supply_driver;
-    if (driver_construct_add(&battery_sense_power_supply_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    extern Driver gpio_hog_driver;
-    if (driver_construct_add(&gpio_hog_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    extern Driver pwm_backlight_driver;
-    if (driver_construct_add(&pwm_backlight_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    extern Driver gpio_backlight_driver;
-    if (driver_construct_add(&gpio_backlight_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    extern Driver rgb_led_gpio_driver;
-    if (driver_construct_add(&rgb_led_gpio_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    extern Driver rgb_led_pwm_driver;
-    if (driver_construct_add(&rgb_led_pwm_driver) != ERROR_NONE) return ERROR_RESOURCE;
-    return ERROR_NONE;
-}
+extern Driver root_driver;
+extern Driver battery_sense_driver;
+extern Driver battery_sense_power_supply_driver;
+extern Driver gpio_hog_driver;
+extern Driver pwm_backlight_driver;
+extern Driver gpio_backlight_driver;
+extern Driver rgb_led_gpio_driver;
+extern Driver rgb_led_pwm_driver;
 
-static error_t stop() {
-    return ERROR_NONE;
-}
+/**
+ * @warning Because the drivers have no owning module, they cannot be unbound.
+ * This is fine for now because we never unload the kernel once it's loaded.
+ */
+static Driver* const KERNEL_DRIVERS[] = {
+    &root_driver,
+    &battery_sense_driver,
+    &battery_sense_power_supply_driver,
+    &gpio_hog_driver,
+    &pwm_backlight_driver,
+    &gpio_backlight_driver,
+    &rgb_led_gpio_driver,
+    &rgb_led_pwm_driver,
+    nullptr,
+};
 
-Module root_module = {
+Module kernel_module = {
     .name = "kernel",
-    .start = start,
-    .stop = stop,
-    .symbols = (const struct ModuleSymbol*)KERNEL_SYMBOLS,
-    .internal = nullptr
+    .start = nullptr,
+    .stop = nullptr,
+    .drivers = KERNEL_DRIVERS,
+    .symbols = static_cast<const struct ModuleSymbol*>(KERNEL_SYMBOLS),
+    .internal = nullptr,
 };
 
 error_t kernel_init(Module* const dts_modules[], const DtsDevice dts_devices[]) {
     LOG_I(TAG, "init");
 
-    if (module_construct_add_start(&root_module) != ERROR_NONE) {
+    if (module_construct_add_start(&kernel_module) != ERROR_NONE) {
         LOG_E(TAG, "root module init failed");
         return ERROR_RESOURCE;
     }

TactilityKernel/source/symbols.c

@@ -570,5 +570,5 @@ const struct ModuleSymbol KERNEL_SYMBOLS[] = {
     DEFINE_MODULE_SYMBOL(properties_file_set),
     DEFINE_MODULE_SYMBOL(properties_file_for_each),
     // terminator
-    MODULE_SYMBOL_TERMINATOR
+    MODULE_SYMBOL_TERMINATOR,
 };