Posted on June 24, 2017 at 14:53Hi there,
I'm facing some problem in getting a STM32L072 MCU in DFU (USB) mode by jumping to the Bootloader in-code.
Following other posts suggestion and the AN2606 i've written these two functions:
#define
RESET_TO_BOOTLOADER_MAGIC_CODE 0xCAFEBABE
uint32_t
dfu_reset_to_bootloader_magic;
1) The function that I call to set a token in memory and trigger a soft-reset:
/*
* Jump to the DFU Mode for firmware upgrade using USB
*/
void
dfuse_RunBootloader(
void
)
{
dfu_reset_to_bootloader_magic = RESET_TO_BOOTLOADER_MAGIC_CODE;
NVIC_SystemReset();
}
2) The function that get executed as first function in the main:
/*
* Check if a DfuSe
Bootloader
request was triggered
* and jump to the dedicated internal routine.
*/
void
dfuse_CheckAndRun(
void
)
{
if
(dfu_reset_to_bootloader_magic == RESET_TO_BOOTLOADER_MAGIC_CODE) {
dfu_reset_to_bootloader_magic = 0;
// Just to be sure that's all de-initialised
HAL_RCC_DeInit();
HAL_DeInit();
__HAL_REMAPMEMORY_SYSTEMFLASH();
__ASM
volatile
(
'
movs
r3, #0\
nldr
r3, [r3, #0]\nMSR
msp
, r3\n'
: : :
'r3'
,
'
sp
'
);
// Application Interrupt and Reset Control :: resetting the peripherals, change the value to 0x05FA0001
{
#define
SCB_AIRCR_VECTKEY_RESET (0x05FA0001)
SCB->
AIRCR
= SCB_AIRCR_VECTKEY_RESET;
}
((
void
(*)(
void
)) *((
uint32_t
*) 0x00000004))();
}
}
After the jump, the MCU goes correctly to the System Flash Memory area containing the Bootloader but no DFU USB device appears in Windows (so nothing can be done with DfuSe).
Did I miss something before the jump to the code / did I made some code error?
Thank you for your help and I hope this question will help also other people!
Davide
