boot from bank2, BFB2 bit, SYSCFG_MEMRMP

[jonfs2000]

Posted on February 14, 2014 at 11:40

I am confused with these lines on Ref. Manual(0090) RM Rev.6 Page70 of 1710 (6th? para)

To select the boot from Flash memory bank 2, clear the BFB2 bit in the user option bytes. When this bit is set and the boot pins are in the boot from main Flash memory configuration, the device boots from system memory, and the boot loader jumps to execute the user application programmed in Flash memory bank 2. For further details, please refer to AN2606.

Also can someone explain what the SYSCFG_MEMRMP does?

Can I reprogram the embedded bootloader in system memory pre programmed by ST? Thank you John #bootloader #syscfg_memrmp

[chen]

Posted on February 14, 2014 at 13:55

Hi

''

Can I reprogram the embedded bootloader in system memory pre programmed by ST?

'' No. What that paragraph is saying is that the option bytes control where the ARM processor will look for code to run at start. The option bytes can be set independent of the program binary. The processor will always try to start code at address 0x00000000 but this can be remapped. ''

Also can someone explain what the SYSCFG_MEMRMP does?

'' This is part of the remapping of 0x00000000 mechanism. It remaps to: 0x800000000 (normal boot location)

bootloader in system memory pre programmed by ST

0x8080000 (I think that is the address of Bank 2) 0x2000000 - SRAM - so that you can run code in RAM

[Tesla DeLorean]

Posted on February 14, 2014 at 16:34

The boot from second bank is overly awkward. The device will boot into the System Loader, which will than sanity check the memory in the upper bank, before switching the mapping (0x08000000 <-> 0x08100000), and booting as if the where at 0x08000000/0x00000000.

To put a secondary image there, you'd build it the same way you'd do for the first 1 MB. The method allows you to switch between two images OLD/NEW, or Image#1/Image#2No you don't get reprogram the System Loader. I suspect if you were buying a million parts ST would entertain your request for a custom one.