stm32/boardctrl: Give boards control over execution of boot.py,main.py.

This commit simplifies the customisation of the main MicroPython execution
loop (4 macros are reduced to 2), and allows a board to have full control
over the execution (or not) of boot.py and main.py.

For boards that use the default start-up code, there is no functional
change in this commit.

Signed-off-by: Damien George <damien@micropython.org>

3 files changed, 56 insertions, 62 deletions

diff --git a/ports/stm32/boardctrl.c b/ports/stm32/boardctrl.c
index 188068d70..c82fefa97 100644
--- a/ports/stm32/boardctrl.c
+++ b/ports/stm32/boardctrl.c
@@ -24,6 +24,7 @@
  * THE SOFTWARE.
  */
 
+#include "py/runtime.h"
 #include "py/mphal.h"
 #include "lib/utils/pyexec.h"
 #include "boardctrl.h"
@@ -140,13 +141,21 @@ void boardctrl_top_soft_reset_loop(boardctrl_state_t *state) {
     led_state(4, 0);
 }
 
-void boardctrl_before_boot_py(boardctrl_state_t *state) {
-    state->run_boot_py = state->reset_mode == 1 || state->reset_mode == 3;
-}
+int boardctrl_run_boot_py(boardctrl_state_t *state) {
+    bool run_boot_py = state->reset_mode == 1 || state->reset_mode == 3;
+
+    if (run_boot_py) {
+        // Run boot.py, if it exists.
+        const char *boot_py = "boot.py";
+        int ret = pyexec_file_if_exists(boot_py);
 
-void boardctrl_after_boot_py(boardctrl_state_t *state) {
-    if (state->run_boot_py && !state->last_ret) {
-        flash_error(4);
+        // Take action based on the execution result.
+        if (ret & PYEXEC_FORCED_EXIT) {
+            return BOARDCTRL_GOTO_SOFT_RESET_EXIT;
+        }
+        if (!ret) {
+            flash_error(4);
+        }
     }
 
     // Turn boot-up LEDs off
@@ -160,17 +169,34 @@ void boardctrl_after_boot_py(boardctrl_state_t *state) {
     led_state(2, 0);
     led_state(3, 0);
     led_state(4, 0);
+
+    return BOARDCTRL_CONTINUE;
 }
 
-void boardctrl_before_main_py(boardctrl_state_t *state) {
-    state->run_main_py = (state->reset_mode == 1 || state->reset_mode == 3)
+int boardctrl_run_main_py(boardctrl_state_t *state) {
+    bool run_main_py = (state->reset_mode == 1 || state->reset_mode == 3)
         && pyexec_mode_kind == PYEXEC_MODE_FRIENDLY_REPL;
-}
 
-void boardctrl_after_main_py(boardctrl_state_t *state) {
-    if (state->run_main_py && !state->last_ret) {
-        flash_error(3);
+    if (run_main_py) {
+        // Run main.py (or what it was configured to be), if it exists.
+        const char *main_py;
+        if (MP_STATE_PORT(pyb_config_main) == MP_OBJ_NULL) {
+            main_py = "main.py";
+        } else {
+            main_py = mp_obj_str_get_str(MP_STATE_PORT(pyb_config_main));
+        }
+        int ret = pyexec_file_if_exists(main_py);
+
+        // Take action based on the execution result.
+        if (ret & PYEXEC_FORCED_EXIT) {
+            return BOARDCTRL_GOTO_SOFT_RESET_EXIT;
+        }
+        if (!ret) {
+            flash_error(3);
+        }
     }
+
+    return BOARDCTRL_CONTINUE;
 }
 
 void boardctrl_start_soft_reset(boardctrl_state_t *state) {
diff --git a/ports/stm32/boardctrl.h b/ports/stm32/boardctrl.h
index f1cbc3b95..33e71b65c 100644
--- a/ports/stm32/boardctrl.h
+++ b/ports/stm32/boardctrl.h
@@ -44,20 +44,12 @@
 #define MICROPY_BOARD_TOP_SOFT_RESET_LOOP boardctrl_top_soft_reset_loop
 #endif
 
-#ifndef MICROPY_BOARD_BEFORE_BOOT_PY
-#define MICROPY_BOARD_BEFORE_BOOT_PY boardctrl_before_boot_py
+#ifndef MICROPY_BOARD_RUN_BOOT_PY
+#define MICROPY_BOARD_RUN_BOOT_PY boardctrl_run_boot_py
 #endif
 
-#ifndef MICROPY_BOARD_AFTER_BOOT_PY
-#define MICROPY_BOARD_AFTER_BOOT_PY boardctrl_after_boot_py
-#endif
-
-#ifndef MICROPY_BOARD_BEFORE_MAIN_PY
-#define MICROPY_BOARD_BEFORE_MAIN_PY boardctrl_before_main_py
-#endif
-
-#ifndef MICROPY_BOARD_AFTER_MAIN_PY
-#define MICROPY_BOARD_AFTER_MAIN_PY boardctrl_after_main_py
+#ifndef MICROPY_BOARD_RUN_MAIN_PY
+#define MICROPY_BOARD_RUN_MAIN_PY boardctrl_run_main_py
 #endif
 
 #ifndef MICROPY_BOARD_START_SOFT_RESET
@@ -68,20 +60,20 @@
 #define MICROPY_BOARD_END_SOFT_RESET boardctrl_end_soft_reset
 #endif
 
+enum {
+    BOARDCTRL_CONTINUE,
+    BOARDCTRL_GOTO_SOFT_RESET_EXIT,
+};
+
 typedef struct _boardctrl_state_t {
     uint8_t reset_mode;
-    bool run_boot_py;
-    bool run_main_py;
     bool log_soft_reset;
-    int last_ret;
 } boardctrl_state_t;
 
 void boardctrl_before_soft_reset_loop(boardctrl_state_t *state);
 void boardctrl_top_soft_reset_loop(boardctrl_state_t *state);
-void boardctrl_before_boot_py(boardctrl_state_t *state);
-void boardctrl_after_boot_py(boardctrl_state_t *state);
-void boardctrl_before_main_py(boardctrl_state_t *state);
-void boardctrl_after_main_py(boardctrl_state_t *state);
+int boardctrl_run_boot_py(boardctrl_state_t *state);
+int boardctrl_run_main_py(boardctrl_state_t *state);
 void boardctrl_start_soft_reset(boardctrl_state_t *state);
 void boardctrl_end_soft_reset(boardctrl_state_t *state);
 
diff --git a/ports/stm32/main.c b/ports/stm32/main.c
index 888b20513..bc8e6f069 100644
--- a/ports/stm32/main.c
+++ b/ports/stm32/main.c
@@ -469,9 +469,7 @@ void stm32_main(uint32_t reset_mode) {
 
     boardctrl_state_t state;
     state.reset_mode = reset_mode;
-    state.run_boot_py = false;
-    state.run_main_py = false;
-    state.last_ret = 0;
+    state.log_soft_reset = false;
 
     MICROPY_BOARD_BEFORE_SOFT_RESET_LOOP(&state);
 
@@ -566,20 +564,11 @@ soft_reset:
     // reset config variables; they should be set by boot.py
     MP_STATE_PORT(pyb_config_main) = MP_OBJ_NULL;
 
-    MICROPY_BOARD_BEFORE_BOOT_PY(&state);
-
-    // run boot.py, if it exists
-    // TODO perhaps have pyb.reboot([bootpy]) function to soft-reboot and execute custom boot.py
-    if (state.run_boot_py) {
-        const char *boot_py = "boot.py";
-        state.last_ret = pyexec_file_if_exists(boot_py);
-        if (state.last_ret & PYEXEC_FORCED_EXIT) {
-            goto soft_reset_exit;
-        }
+    // Run boot.py (or whatever else a board configures at this stage).
+    if (MICROPY_BOARD_RUN_BOOT_PY(&state) == BOARDCTRL_GOTO_SOFT_RESET_EXIT) {
+        goto soft_reset_exit;
     }
 
-    MICROPY_BOARD_AFTER_BOOT_PY(&state);
-
     // Now we initialise sub-systems that need configuration from boot.py,
     // or whose initialisation can be safely deferred until after running
     // boot.py.
@@ -613,24 +602,11 @@ soft_reset:
 
     // At this point everything is fully configured and initialised.
 
-    MICROPY_BOARD_BEFORE_MAIN_PY(&state);
-
-    // Run the main script from the current directory.
-    if (state.run_main_py) {
-        const char *main_py;
-        if (MP_STATE_PORT(pyb_config_main) == MP_OBJ_NULL) {
-            main_py = "main.py";
-        } else {
-            main_py = mp_obj_str_get_str(MP_STATE_PORT(pyb_config_main));
-        }
-        state.last_ret = pyexec_file_if_exists(main_py);
-        if (state.last_ret & PYEXEC_FORCED_EXIT) {
-            goto soft_reset_exit;
-        }
+    // Run main.py (or whatever else a board configures at this stage).
+    if (MICROPY_BOARD_RUN_MAIN_PY(&state) == BOARDCTRL_GOTO_SOFT_RESET_EXIT) {
+        goto soft_reset_exit;
     }
 
-    MICROPY_BOARD_AFTER_MAIN_PY(&state);
-
     #if MICROPY_ENABLE_COMPILER
     // Main script is finished, so now go into REPL mode.
     // The REPL mode can change, or it can request a soft reset.