Use Thumb mode jump address for GO command

ernsts · tormodvolden · commit 23e658374cb1 · 2016-02-08T18:27:44.000+01:00
As discussed in the ST forums [1], the bootloader requires an odd (Thumb mode) address for the GO command. If an even address is used, the Cortex M does something like a software reset, but this is not generated by the write to AICR in stm_reset_code, but by an exception due to the even address which is not compatible with Thumb mode. ARM specifies 'Hard Fault' for this case: http://infocenter.arm.com/help/ index.jsp?topic=/com.arm.doc.dui0497a/BABDCDHA.html [1] https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/System%20boot%20mode%20and%20Go%20command%20STM32f103rbt6 Signed-off-by: Ernst Schwab <eschwab@online.de>
diff --git a/stm32.c b/stm32.c
@@ -880,7 +880,7 @@ static stm32_err_t stm32_run_raw_code(const stm32_t *stm,
 				      const uint8_t *code, uint32_t code_size)
 {
 	uint32_t stack_le = le_u32(0x20002000);
-	uint32_t code_address_le = le_u32(target_address + 8);
+	uint32_t code_address_le = le_u32(target_address + 8 + 1); // thumb mode address (!)
 	uint32_t length = code_size + 8;
 	uint8_t *mem, *pos;
 	uint32_t address, w;

Original file line number	Diff line number	Diff line change
`@@ -880,7 +880,7 @@ static stm32_err_t stm32_run_raw_code(const stm32_t *stm,`
`880`	`880`	`const uint8_t *code, uint32_t code_size)`
`881`	`881`	`{`
`882`	`882`	`uint32_t stack_le = le_u32(0x20002000);`
`883`		`- uint32_t code_address_le = le_u32(target_address + 8);`
	`883`	`+ uint32_t code_address_le = le_u32(target_address + 8 + 1); // thumb mode address (!)`
`884`	`884`	`uint32_t length = code_size + 8;`
`885`	`885`	`uint8_t mem, pos;`
`886`	`886`	`uint32_t address, w;`