| Message ID | 20230403121537.71320-1-lucas@osdyne.com |
|---|---|
| State | New |
| Headers | show |
| Series | stm32vldiscovery: allow overriding of RAM size | expand |
On Mon, 3 Apr 2023 at 13:51, Lucas Villa Real <lucasvr@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 <lucas@osdyne.com> Does the real hardware have (options for) more than 8K of SRAM here ? thanks -- PMM
On Mon, Apr 3, 2023 at 10:54 AM Peter Maydell <peter.maydell@linaro.org> wrote: > On Mon, 3 Apr 2023 at 13:51, Lucas Villa Real <lucasvr@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 <lucas@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
On 4/3/23 16:48, Lucas C. Villa Real wrote: > On Mon, Apr 3, 2023 at 10:54 AM Peter Maydell <peter.maydell@linaro.org > <mailto:peter.maydell@linaro.org>> wrote: > > On Mon, 3 Apr 2023 at 13:51, Lucas Villa Real <lucasvr@gmail.com > <mailto:lucasvr@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 <lucas@osdyne.com > <mailto:lucas@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. Thanks,
On Tue, Apr 4, 2023 at 3:23 AM Alexandre IOOSS <erdnaxe@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.maydell@linaro.org > > <mailto:peter.maydell@linaro.org>> wrote: > > > > On Mon, 3 Apr 2023 at 13:51, Lucas Villa Real <lucasvr@gmail.com > > <mailto:lucasvr@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 <lucas@osdyne.com > > <mailto:lucas@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
diff --git a/hw/arm/stm32vldiscovery.c b/hw/arm/stm32vldiscovery.c index 67675e952f..7ca3ba029e 100644 --- a/hw/arm/stm32vldiscovery.c +++ b/hw/arm/stm32vldiscovery.c @@ -29,6 +29,7 @@ #include "hw/qdev-properties.h" #include "hw/qdev-clock.h" #include "qemu/error-report.h" +#include "exec/address-spaces.h" #include "hw/arm/stm32f100_soc.h" #include "hw/arm/boot.h" @@ -42,6 +43,9 @@ static void stm32vldiscovery_init(MachineState *machine) DeviceState *dev; Clock *sysclk; + /* Allow overriding the emulated board's RAM size */ + memory_region_add_subregion(get_system_memory(), SRAM_BASE_ADDRESS, machine->ram); + /* This clock doesn't need migration because it is fixed-frequency */ sysclk = clock_new(OBJECT(machine), "SYSCLK"); clock_set_hz(sysclk, SYSCLK_FRQ); @@ -60,6 +64,8 @@ static void stm32vldiscovery_machine_init(MachineClass *mc) { mc->desc = "ST STM32VLDISCOVERY (Cortex-M3)"; mc->init = stm32vldiscovery_init; + mc->default_ram_id = "stm32vldiscovery.ram"; + mc->default_ram_size = SRAM_SIZE; } DEFINE_MACHINE("stm32vldiscovery", stm32vldiscovery_machine_init)
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 <lucas@osdyne.com> --- hw/arm/stm32vldiscovery.c | 6 ++++++ 1 file changed, 6 insertions(+)