On Fri, Sep 3, 2010 at 9:29 PM, John Hartman (NoICE) <j...@noicedebugger.com> wrote: > The STM32 parts have Flash beginning at 0x8000000, and OpenOCD's stm32x.c > places the Flash there regardless of the address used in the "flash" command > in the cfg file. > > The chips have two pins that can be jumpered to specify what appears at > address 0: Flash, RAM, or the boot loader. For embedded work, I think > "Flash" will be the most common case. > > But if I link my program at zero, it is a pain to burn my program, because > OpenOCD tells gdb there is only RAM at 0, with Flash at 8000000. > > One solution is to re-link my program to 8000000, and rely on aliasing of > the vector table to 0. This works, but is a little annoying.
Annoying how? The flash IS at 0x08000000. Why would you want to link your program to 0? That if anything would be relying on the aliasing. Of course it works, otherwise the chip couldn't start, but does it alias the entire flash and not just enough to cover the vectors? Two years ago, the ST folks I asked didn't know the answer to that. Perhaps it's clarified in the docs today. > I would like to propose the following changes to allow Flash at zero: > > > 1) In the file flash/stm32x.c, function stm32x_probe, remove or comment out > the explicit setting of bank->base: > // Don't fill in the base: get it from the cfg file > // bank->base = 0x08000000; > bank->size = (num_pages * page_size); > (etc.) > > 2) In the stm32.cfg, change > flash bank $_FLASHNAME stm32x 0 0 0 0 $_TARGETNAME > to > flash bank $_FLASHNAME.1 stm32x 0x00000000 0 0 0 $_TARGETNAME > flash bank $_FLASHNAME.2 stm32x 0x08000000 0 0 0 $_TARGETNAME > > This claims that there are TWO Flash banks, one at 0 and one at 8000000. By > having two banks, users can locate their code at either location, as they > prefer, without needing to modify the cfg file. > > Note that this would break existing cfg files, moving the Flash from 8000000 > to 0. This could be remedied by using a non-zero value for one of the other > parameters (bus width etc) to mean "new style", and only using the specified > base address in that case. (Or more formally, one might add a new > "algorithm" instead of stm32x that does this) > > What do people think? Breaking existing config files and/or adding confusing nonexistent banks for no apparent benefit? I don't like it. /Andreas _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
