On Tue, Apr 4, 2023 at 3:23 AM Alexandre IOOSS <erdn...@crans.org> wrote:
> On 4/3/23 16:48, Lucas C. Villa Real wrote: > > On Mon, Apr 3, 2023 at 10:54 AM Peter Maydell <peter.mayd...@linaro.org > > <mailto:peter.mayd...@linaro.org>> wrote: > > > > On Mon, 3 Apr 2023 at 13:51, Lucas Villa Real <luca...@gmail.com > > <mailto:luca...@gmail.com>> wrote: > > > > > > stm32vldiscovery comes with 8KB of SRAM, which may be too low when > > > running some workloads on QEMU. The command line argument "-m > > mem_size" > > > is not recognized by the current implementation, though, so one > > cannot > > > easily override the default memory size. > > > > > > This patch fixes that by adding a memory subregion according to > the > > > value provided on that command line argument. If absent, the > default > > > value of 8KB still applies. > > > > > > Signed-off-by: Lucas Villa Real <lu...@osdyne.com > > <mailto:lu...@osdyne.com>> > > > > Does the real hardware have (options for) more than 8K of SRAM here ? > > > > thanks > > -- PMM > > > > > > Yes, it's possible to add more (p)SRAM via the STM32F10xxx's FSMC > > (flexible static memory controller). The new memory is mapped to FSMC > > bank 1 at 0x6000_0000, though (as opposed to the embedded SRAM's fixed > > address at 0x2000_0000), as I have now realized. I'm happy to send an > > updated patch so that "-m mem_size" creates a memory subregion at > > 0x6000_0000 instead. > > > > Best regards, > > Lucas > > > > Looking at the STM32F100xx reference manual page 494 > ( > https://www.st.com/resource/en/reference_manual/rm0041-stm32f100xx-advanced-armbased-32bit-mcus-stmicroelectronics.pdf), > > FSMC is only present on high-density value line devices only. This is > not the case of the STM32VLDISCOVERY which uses a STM32F100RB > (low/medium-density value line). > > Correct me if I'm wrong, but I believe you cannot buy a STM32VLDISCOVERY > that could support FSMC or have more than 8KB of on-chip SRAM. > > However, could it be a good idea to implement a generic STM32F100xx > machine in QEMU that is "high-density" by default and that could be > configured using command line options ? This could cover a wide range of > cases with a single machine. > Oh, you're right: FSMC is only featured on high-density STM32F100xx devices. Since I'm mostly dealing with QEMU (i.e., no real hardware) at this point in time I wasn't aware of that limitation. Thanks for the heads up. Given that the current STM32 port doesn't implement many devices, I presume that adding support for a "high-density" machine would come down to making changes to the flash and register boundary addresses, mostly? If that's the case, then it makes sense to support such a generic machine. I've limited time to work on that, but I can give it a kick start and we can coordinate offline if that's OK with you. Lucas
