stm32/mboot: Generate FLASH_LAYOUT_STR at runtime on H5 MCUs.

The size of the flash varies among MCU variants. Instead of requiring a build-time variable to configure this, compute it at runtime using the special device information word accessible through the FLASH_SIZE macro. This feature is currently only implemented for H5 MCUs, but can be extended to others. Signed-off-by: Damien George <[email protected]>
IhorNehrutsa · Feb 20, 2024 · 802a88c · 802a88c
1 parent 3db2910
commit 802a88c
Showing 1 changed file with 32 additions and 1 deletion.
diff --git a/ports/stm32/mboot/main.c b/ports/stm32/mboot/main.c
@@ -435,7 +435,7 @@ void mp_hal_pin_config_speed(uint32_t port_pin, uint32_t speed) {
 #elif defined(STM32G0)
 #define FLASH_LAYOUT_STR "@Internal Flash  /0x08000000/256*02Kg" MBOOT_SPIFLASH_LAYOUT MBOOT_SPIFLASH2_LAYOUT
 #elif defined(STM32H5)
-#define FLASH_LAYOUT_STR "@Internal Flash  /0x08000000/256*08Kg" MBOOT_SPIFLASH_LAYOUT MBOOT_SPIFLASH2_LAYOUT
+#define FLASH_LAYOUT_TEMPLATE "@Internal Flash  /0x08000000/???*08Kg" MBOOT_SPIFLASH_LAYOUT MBOOT_SPIFLASH2_LAYOUT
 #elif defined(STM32H743xx)
 #define FLASH_LAYOUT_STR "@Internal Flash  /0x08000000/16*128Kg" MBOOT_SPIFLASH_LAYOUT MBOOT_SPIFLASH2_LAYOUT
 #elif defined(STM32H750xx)
@@ -444,6 +444,25 @@ void mp_hal_pin_config_speed(uint32_t port_pin, uint32_t speed) {
 #define FLASH_LAYOUT_STR "@Internal Flash  /0x08000000/256*04Kg" MBOOT_SPIFLASH_LAYOUT MBOOT_SPIFLASH2_LAYOUT
 #endif
 
+#if !defined(FLASH_LAYOUT_STR)
+
+#define FLASH_LAYOUT_STR_ALLOC (sizeof(FLASH_LAYOUT_TEMPLATE))
+
+// Build the flash layout string from a template with total flash size inserted.
+static size_t build_flash_layout_str(char *buf) {
+    size_t len = FLASH_LAYOUT_STR_ALLOC - 1;
+    memcpy(buf, FLASH_LAYOUT_TEMPLATE, len + 1);
+    unsigned int num_sectors = FLASH_SIZE / FLASH_SECTOR_SIZE;
+    buf += 31; // location of "???" in FLASH_LAYOUT_TEMPLATE
+    for (unsigned int i = 0; i < 3; ++i) {
+        *buf-- = '0' + num_sectors % 10;
+        num_sectors /= 10;
+    }
+    return len;
+}
+
+#endif
+
 static bool flash_is_modifiable_addr_range(uint32_t addr, uint32_t len) {
     return addr + len < (uint32_t)&_mboot_protected_flash_start
            || addr >= (uint32_t)&_mboot_protected_flash_end_exclusive;
@@ -756,8 +775,12 @@ void i2c_slave_process_rx_end(i2c_slave_t *i2c) {
     } else if (buf[0] == I2C_CMD_RESET && len == 0) {
         dfu_context.leave_dfu = true;
     } else if (buf[0] == I2C_CMD_GETLAYOUT && len == 0) {
+        #if defined(FLASH_LAYOUT_STR)
         len = strlen(FLASH_LAYOUT_STR);
         memcpy(buf, FLASH_LAYOUT_STR, len);
+        #else
+        len = build_flash_layout_str(buf);
+        #endif
     } else if (buf[0] == I2C_CMD_MASSERASE && len == 0) {
         len = do_mass_erase();
     } else if (buf[0] == I2C_CMD_PAGEERASE && len == 4) {
@@ -1161,7 +1184,15 @@ static uint8_t *pyb_usbdd_StrDescriptor(USBD_HandleTypeDef *pdev, uint8_t idx, u
         }
 
         case USBD_IDX_CONFIG_STR:
+            #if defined(FLASH_LAYOUT_STR)
             USBD_GetString((uint8_t *)FLASH_LAYOUT_STR, str_desc, length);
+            #else
+            {
+                char buf[FLASH_LAYOUT_STR_ALLOC];
+                build_flash_layout_str(buf);
+                USBD_GetString((uint8_t *)buf, str_desc, length);
+            }
+            #endif
             return str_desc;
 
         case MBOOT_ERROR_STR_OVERWRITE_BOOTLOADER_IDX: