Posted on December 10, 2015 at 09:40Hello
I have a nucleol152 board. As I need to protect a memory area, I used this function to make a read protection + a write protection on zone specific areas:
__IO uint32_t WPR_Value = 0x0, WriteProtectedPages = 0x0;
FLASH_Unlock();
/* Unlock the Option Bytes */
FLASH_OB_Unlock();
/*Set read protection to 1*/
FLASH_OB_RDPConfig(OB_RDP_Level_1);
/* Get pages write protection status */
WPR_Value = FLASH_OB_GetWRP();
/* Get current write protected pages and the new pages to be protected/unprotected */
WriteProtectedPages = (WPR_Value & FLASH_PAGES_TO_BE_WRITE_PROTECTED);
/* Check if desired pages are not yet write protected */
if(WriteProtectedPages != FLASH_PAGES_TO_BE_WRITE_PROTECTED)
{
/* Enable the pages read/write protection */
FLASH_OB_WRPConfig(FLASH_PAGES_TO_BE_WRITE_PROTECTED, DISABLE);
/* Generate System Reset to load the new option byte values */
FLASH_OB_Launch();
}
/* Lock the Option Bytes */
FLASH_OB_Lock();
When I try to reflash my board using the stlink, I have a fail. I understand it fails as memory is protected.
I tried several things to unblock the memory:
I use GDB to write the following sequence
unlock flash
(gdb) set {int}0x40023C10 = 0x8C9DAEBF
(gdb) set {int}0x40023C10 = 0x13141516
unlock OB
(gdb) set {int}0x40023C14 = 0xFBEAD9C8
(gdb) set {int}0x40023C14 = 0x24252627
switch to RDP level 0
(gdb) set {int}0x1FF80000 = 0x000000AA
This last operation always fails and GDB returns that it cannot access to this memory area.
I tried to push this sequence into a RAM program but it still has no effect (unless the code I downloaded is not working well).
I saw this type of topic and I was wondering if it was the only solution to unblock my memory.
http://www.mobilewill.us/2015/06/stm32-nucleo-and-dfu-usb-bootloading.html Could you tell me how I should proceed to unblock the memory?
Thanks for your support
#rdp #nucleo #st-link #swd
