Merge branch 'rahix/lifecycle'

This changeset implements a proper lifecycle of the core 1 payload.
The implementation faces some difficulties because there is no way to
properly reset just core 1.  Instead, we chose a cooperative approach:

To perform a reset, core 1 jumps to a reset-stub and is then fed a new
IVT location which it uses to "restart" with a new payload.  The jump to
the reset-stub is either voluntary by a call to epic_exit() or epix_exec(),
or involuntary by Epicardium issuing a "reset" interrupt.  This is a
special API interrupt whose handler is pre-implemented in the API-caller
lib.

Additionally, this changeset contains support for defining which python
script Pycardium should execute on startup.  This way, scripts can issue
the start of one another using `epic_exec("script-name.py")`.

Finally, this changeset also changes the power-button behavior.
Pressing the power button will now excert the following behavior:

    - `<400 ms`: Return back to menu
    - `<1 s`: Reset card10
    - `>1 s`: Poweroff

Signed-off-by: Rahix <rahix@rahix.de>

l0dables/lib/l0dable.ld

@@ -33,6 +33,9 @@ SECTIONS {
 
     .text :
     {
+        /* The vector table needs 128 byte alignment */
+        . = ALIGN(128);
+        KEEP(*(.text.isr_vector))
         *(.text*)
         *(.rodata*)
 

l0dables/lib/meson.build

@@ -3,7 +3,7 @@ l0dable_startup_lib = static_library(
   'crt.s',
   'hardware.c',
   dependencies: [api_caller],
-  pic: true,
+  c_args: ['-fpie'],
 )
 
 l0dable_startup = declare_dependency(

meson.build

@@ -28,6 +28,13 @@ if get_option('debug_prints')
   )
 endif
 
+if get_option('debug_core1')
+  add_global_arguments(
+    ['-DCARD10_DEBUG_CORE1=1'],
+    language: 'c',
+  )
+endif
+
 add_global_link_arguments(
   '-Wl,--gc-sections',
   '-lm',

meson_options.txt

@@ -6,6 +6,14 @@ option(
   description: 'Whether to print debug messages on the serial console'
 )
 
+option(
+  'debug_core1',
+  type: 'boolean',
+  value: false,
+
+  description: 'Enable core 1 debugging interface'
+)
+
 option(
   'ble_trace',
   type: 'boolean',

pycardium/main.c

 #include "epicardium.h"
+#include "api/caller.h"
 #include "mphalport.h"
 #include "card10-version.h"
 
@@ -24,10 +25,19 @@ static const char header[] =
 
 int main(void)
 {
-	epic_uart_write_str(header, sizeof(header));
+	char script_name[128] = { 0 };
+	int cnt = api_fetch_args(script_name, sizeof(script_name));
 
 	pycardium_hal_init();
 
+	epic_uart_write_str(header, sizeof(header));
+
+	if (cnt < 0) {
+		printf("pycardium: Error fetching args: %d\n", cnt);
+	} else if (cnt > 0) {
+		printf("  Loading %s ...\n", script_name);
+	}
+
 	mp_stack_set_top(&__StackTop);
 	mp_stack_set_limit((mp_int_t)&__StackLimit);
 
@@ -35,12 +45,22 @@ int main(void)
 		gc_init(&__HeapBase + 1024 * 10, &__HeapLimit);
 
 		mp_init();
-		pyexec_file_if_exists("main.py");
+
+		if (cnt > 0) {
+			pyexec_file_if_exists(script_name);
+		}
+
 		pyexec_friendly_repl();
+
 		mp_deinit();
 	}
 }
 
+void HardFault_Handler(void)
+{
+	epic_exit(255);
+}
+
 void gc_collect(void)
 {
 	void *sp = (void *)__get_MSP();

pycardium/meson.build

@@ -6,6 +6,7 @@ modsrc = files(
   'modules/interrupt.c',
   'modules/sys_leds.c',
   'modules/light_sensor.c',
+  'modules/os.c',
   'modules/sys_display.c',
   'modules/utime.c',
   'modules/vibra.c',

pycardium/modules/os.c

+#include "epicardium.h"
+
+#include "py/obj.h"
+#include "py/runtime.h"
+
+#include <string.h>
+
+static mp_obj_t mp_os_exit(size_t n_args, const mp_obj_t *args)
+{
+	int ret = 0;
+	if (n_args == 1) {
+		ret = mp_obj_get_int(args[0]);
+	}
+
+	epic_exit(ret);
+
+	/* unreachable */
+	return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(exit_obj, 0, 1, mp_os_exit);
+
+static mp_obj_t mp_os_exec(mp_obj_t name_in)
+{
+	const char *name_ptr;
+	char name_str[256];
+	size_t len, maxlen;
+
+	name_ptr = mp_obj_str_get_data(name_in, &len);
+
+	/*
+	 * The string retrieved from MicroPython is not NULL-terminated so we
+	 * first need to copy it and add a NULL-byte.
+	 */
+	maxlen = len < (sizeof(name_str) - 1) ? len : (sizeof(name_str) - 1);
+	memcpy(name_str, name_ptr, maxlen);
+	name_str[maxlen] = '\0';
+
+	int ret = epic_exec(name_str);
+
+	/*
+	 * If epic_exec() returns, something went wrong.  We can raise an
+	 * exception in all cases.
+	 */
+	mp_raise_OSError(-ret);
+
+	/* unreachable */
+	return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(exec_obj, mp_os_exec);
+
+static const mp_rom_map_elem_t os_module_gobals_table[] = {
+	{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_os) },
+	{ MP_ROM_QSTR(MP_QSTR_exit), MP_ROM_PTR(&exit_obj) },
+	{ MP_ROM_QSTR(MP_QSTR_exec), MP_ROM_PTR(&exec_obj) },
+};
+static MP_DEFINE_CONST_DICT(os_module_globals, os_module_gobals_table);
+
+const mp_obj_module_t os_module = {
+	.base    = { &mp_type_module },
+	.globals = (mp_obj_dict_t *)&os_module_globals,
+};
+
+/* This is a special macro that will make MicroPython aware of this module */
+/* clang-format off */
+MP_REGISTER_MODULE(MP_QSTR_os, os_module, MODULE_OS_ENABLED);

pycardium/modules/qstrdefs.h

@@ -85,3 +85,7 @@ Q(tell)
 Q(TextIOWrapper)
 Q(write)
 
+/* os */
+Q(os)
+Q(exit)
+Q(exec)

pycardium/mpconfigport.h

@@ -43,6 +43,7 @@
 #define MODULE_INTERRUPT_ENABLED            (1)
 #define MODULE_LEDS_ENABLED                 (1)
 #define MODULE_LIGHT_SENSOR_ENABLED         (1)
+#define MODULE_OS_ENABLED                   (1)
 #define MODULE_UTIME_ENABLED                (1)
 #define MODULE_VIBRA_ENABLED                (1)