Marek Vasut marex@denx.de schrieb am Do., 13. Juni 2019, 22:56:
On 6/13/19 10:55 PM, Simon Goldschmidt wrote:
Marek Vasut <marex@denx.de mailto:marex@denx.de> schrieb am Do., 13. Juni 2019, 22:40:
On 6/13/19 10:26 PM, Simon Goldschmidt wrote: > > > On 13.06.19 22:14, Marek Vasut wrote: >> On 6/13/19 9:50 PM, Simon Goldschmidt wrote: >>> This provides an SPL_SIZE_LIMIT that makes the build check that the SPL >>> binary loaded from flash fits into the SRAM (64 KiB) and leaves enough >>> room for global data, heap and stack (512 bytes assumed stack usage). >>> >>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com <mailto:simon.k.r.goldschmidt@gmail.com>> >>> --- >>> >>> arch/arm/mach-socfpga/Kconfig | 8 ++++++++ >>> 1 file changed, 8 insertions(+) >>> >>> diff --git a/arch/arm/mach-socfpga/Kconfig >>> b/arch/arm/mach-socfpga/Kconfig >>> index 48f02f08d4..1d914648e3 100644 >>> --- a/arch/arm/mach-socfpga/Kconfig >>> +++ b/arch/arm/mach-socfpga/Kconfig >>> @@ -3,6 +3,12 @@ if ARCH_SOCFPGA >>> config NR_DRAM_BANKS >>> default 1 >>> +config SPL_SIZE_LIMIT >>> + default 65536 if TARGET_SOCFPGA_GEN5 >>> + >>> +config SPL_SIZE_LIMIT_PROVIDE_STACK >>> + default 0x200 if TARGET_SOCFPGA_GEN5 >>> + >>> config SPL_STACK_R_ADDR >>> default 0x00800000 if TARGET_SOCFPGA_GEN5 >>> @@ -49,6 +55,8 @@ config TARGET_SOCFPGA_GEN5 >>> bool >>> select SPL_ALTERA_SDRAM >>> imply FPGA_SOCFPGA >>> + imply SPL_SIZE_LIMIT_SUBTRACT_GD >>> + imply SPL_SIZE_LIMIT_SUBTRACT_MALLOC >>> imply SPL_STACK_R >>> imply SPL_SYS_MALLOC_SIMPLE >>> imply USE_TINY_PRINTF >>> >> 512 bytes for stack looks like it's too little. I think the SPL started >> misbehaving when it overgrew 50 kiB, no ? > > To 1: Well, I tested the stack usage once, booting from eMMC, andwas
> somewhere below that range. But yes, it's a problem for the future: once > we get a more stack-consuming function, we might be lost. Whichsize
> would you suggest? Hmmm, now that I think about it, the stack gets relocated to DRAMquite
early too, right ? So maybe we really don't need that much space for stack.Exactly. The only stack-consuming things before relocation are dts parsing and maybe the ddr driver. I implemented a stack usage check by filling the memory with 0xaa and checking it afterwards and if I remember correctly it resulted in about 400 bytes. It's even more or less independent of the boot type since the ski/mmc drivers are probed only after DDR is up. Same goes for file systems.
Nevertheless, stack usage can increase in the future. That's why I'm not too happy about this constant. Otoh, DM_CLK makes me need every byte and right now I don't see how I can enable secure boot (fit signature check) due to this size limit...
Maybe before we add more bloat, we should consider how to trim the bloat down first ?
One of the reasons why I haven't sent the clk driver patches yet.
Anyway, I'll be off for at least a week now, I just wanted to get this one in before the release.
I hope I'll be working on SPL size after that... 64 KiB not being enough is just ridicculous...
Regards, Simon