Re: [U-Boot] [PATCH] arm: socfpga: provide default SPL_SIZE_LIMIT for gen5

Marek Vasut marex@denx.de schrieb am Do., 13. Juni 2019, 23:08:

On 6/13/19 11:00 PM, Simon Goldschmidt wrote:

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Marek Vasut <marex@denx.de mailto: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>
<mailto: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>
>     <mailto: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

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>     started
>     >> misbehaving when it overgrew 50 kiB, no ?
>     >
>     > To 1: Well, I tested the stack usage once, booting from
eMMC, and was
>     > 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.
Which size
>     > would you suggest?
>
>     Hmmm, now that I think about it, the stack gets relocated to
DRAM quite
>     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

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> 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

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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.

So is 0x200 bytes for stack before SPL relocs the stack enough ?

For now it's enough, yes.

Regards, Simon

...

I hope I'll be working on SPL size after that... 64 KiB not being enough is just ridicculous...

Agreed

-- Best regards, Marek Vasut