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The following commit(s) were added to refs/heads/master by this push:
new 6b5673a4336 stm32g0: Add flash bank swap support
6b5673a4336 is described below
commit 6b5673a4336526ee4cfe081d246e1f0e354a93f0
Author: jsanchez-2g <[email protected]>
AuthorDate: Thu Sep 3 14:31:44 2026 -0500
stm32g0: Add flash bank swap support
Add APIs to toggle the dual-bank flash mapping and reload the option bytes.
Reject bank swapping when BOOT_LOCK is enabled and leave the swap operation as
a no-op on single-bank devices.
Assisted-by: OpenAI Codex <[email protected]>
Signed-off-by: jsanchez-2g <[email protected]>
---
arch/arm/src/common/stm32/stm32_flash.h | 2 +
arch/arm/src/common/stm32/stm32_flash_m0_g0c0.c | 91 +++++++++++++++++++++++++
2 files changed, 93 insertions(+)
diff --git a/arch/arm/src/common/stm32/stm32_flash.h
b/arch/arm/src/common/stm32/stm32_flash.h
index 9050b255d6b..716323b4c16 100644
--- a/arch/arm/src/common/stm32/stm32_flash.h
+++ b/arch/arm/src/common/stm32/stm32_flash.h
@@ -46,6 +46,8 @@
void stm32_flash_getopt(uint32_t *opt);
int stm32_flash_optmodify(uint32_t clear, uint32_t set);
+int stm32_flash_optload(void);
+int stm32_flash_swapbanks(void);
void stm32_flash_lock(void);
void stm32_flash_unlock(void);
diff --git a/arch/arm/src/common/stm32/stm32_flash_m0_g0c0.c
b/arch/arm/src/common/stm32/stm32_flash_m0_g0c0.c
index 7b4d5e1e5e9..a44a6b06bfa 100644
--- a/arch/arm/src/common/stm32/stm32_flash_m0_g0c0.c
+++ b/arch/arm/src/common/stm32/stm32_flash_m0_g0c0.c
@@ -588,6 +588,97 @@ int stm32_flash_optmodify(uint32_t clear, uint32_t set)
return 0;
}
+/****************************************************************************
+ * Name: stm32_flash_optload
+ *
+ * Description:
+ * Reload the flash option bytes. If an option-byte change affects the
+ * flash-bank mapping, the reload immediately resets the system.
+ *
+ * Returned Value:
+ * Zero or a negated errno value.
+ *
+ * -EBUSY: Timeout waiting for a previous flash operation to finish.
+ *
+ ****************************************************************************/
+
+int stm32_flash_optload(void)
+{
+ int ret;
+ bool was_locked;
+
+ ret = flash_wait_for_operation();
+ if (ret != 0)
+ {
+ return -EBUSY;
+ }
+
+ was_locked = flash_unlock_opt();
+ modifyreg32(STM32_FLASH_SR, 0, FLASH_SR_CLEAR_ERROR_FLAGS);
+
+ ret = flash_wait_for_operation();
+ if (ret != 0)
+ {
+ ret = -EBUSY;
+ goto exit;
+ }
+
+ modifyreg32(STM32_FLASH_CR, 0, FLASH_CR_OBL_LAUNCH);
+
+ while (getreg32(STM32_FLASH_CR) & FLASH_CR_OBL_LAUNCH)
+ {
+ }
+
+exit:
+ if (was_locked)
+ {
+ flash_lock_opt();
+ }
+
+ return ret;
+}
+
+/****************************************************************************
+ * Name: stm32_flash_swapbanks
+ *
+ * Description:
+ * Toggle the flash-bank mapping in the option bytes. The new mapping takes
+ * effect after a power-on reset or a call to stm32_flash_optload().
+ *
+ * Returned Value:
+ * Zero or a negated errno value.
+ *
+ * -EBUSY: Timeout waiting for a previous flash operation to finish.
+ * -EPERM: Bank swapping is prohibited by the boot lock.
+ *
+ ****************************************************************************/
+
+int stm32_flash_swapbanks(void)
+{
+ int ret = 0;
+
+#ifdef FLASH_DUAL_BANK
+ uint32_t reg;
+
+ if (getreg32(STM32_FLASH_SECR) & FLASH_SECR_BOOT_LOCK)
+ {
+ return -EPERM;
+ }
+
+ reg = getreg32(STM32_FLASH_OPTR);
+ if (reg & FLASH_OPTR_NSWAP_BANK)
+ {
+ ret = stm32_flash_optmodify(FLASH_OPTR_NSWAP_BANK, 0);
+ }
+ else
+ {
+ ret = stm32_flash_optmodify(0, FLASH_OPTR_NSWAP_BANK);
+ }
+#endif
+
+ return ret;
+}
+
#ifdef CONFIG_ARCH_HAVE_PROGMEM
/* up_progmem_x functions defined in nuttx/include/nuttx/progmem.h
