[U-Boot] [PATCH] arm: socfpga: check total size of SPL

[Simon Goldschmidt]

On Thu, Nov 1, 2018 at 8:26 PM Simon Goldschmidt
<simon.k.r.goldschmidt at gmail.com> wrote:
>
> On 31.10.2018 11:00, Marek Vasut wrote:
> > On 10/31/2018 06:44 AM, Simon Goldschmidt wrote:
> >> On Tue, Oct 30, 2018 at 11:02 PM Marek Vasut <marek.vasut at gmail.com> wrote:
> >>> On 10/30/2018 10:30 PM, Simon Goldschmidt wrote:
> >>>> On 30.10.2018 22:26, Marek Vasut wrote:
> >>>>> On 10/30/2018 10:23 PM, Simon Goldschmidt wrote:
> >>>>>> Correctly define CONFIG_SPL_MAX_FOOTPRINT to make the default arm
> >>>>>> linker script for SPL check the total SRAM size available for SPL
> >>>>>> (code, data, bss, heap, global data).
> >>>>>>
> >>>>>> The previously existing define CONFIG_SPL_MAX_SIZE seems to only
> >>>>>> check the binary size (which is without bss, heap and gd).
> >>>>>>
> >>>>>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt at gmail.com>
> >>>>>> ---
> >>>>>>
> >>>>>>    include/configs/socfpga_common.h | 7 +++++++
> >>>>>>    1 file changed, 7 insertions(+)
> >>>>>>
> >>>>>> diff --git a/include/configs/socfpga_common.h
> >>>>>> b/include/configs/socfpga_common.h
> >>>>>> index 2330143cf1..9103d0a966 100644
> >>>>>> --- a/include/configs/socfpga_common.h
> >>>>>> +++ b/include/configs/socfpga_common.h
> >>>>>> @@ -242,6 +242,13 @@ unsigned int cm_get_qspi_controller_clk_hz(void);
> >>>>>>    #define CONFIG_SPL_TEXT_BASE        CONFIG_SYS_INIT_RAM_ADDR
> >>>>>>    #define CONFIG_SPL_MAX_SIZE        CONFIG_SYS_INIT_RAM_SIZE
> >>>>>>    +/* Check total size of SPL including BSS, malloc area and gd */
> >>>>>> +#include <generated/generic-asm-offsets.h>
> >>>>>> +#define CONFIG_SPL_MAX_FOOTPRINT    (CONFIG_SYS_INIT_SP_ADDR - \
> >>>>>> +                     CONFIG_SYS_INIT_RAM_ADDR - \
> >>>>>> +                     CONFIG_SYS_MALLOC_F_LEN - \
> >>>>>> +                     GENERATED_GBL_DATA_SIZE)
> >>>>> Are you sure this calculation is correct ? INIT_SP_ADDR is I think the
> >>>>> SRAM offset in the address space. Shouldn't that contain INIT_SP_SIZE or
> >>>>> something ?
> >>>> Yes, I'm pretty sure. INIT_SP_ADDR is defined as INIT_RAM_ADDR +
> >>>> INIT_RAM_SIZE.
> >>>> So by subtracting INIT_RAM_ADDR again, I effectively get "INIT_RAM_ADDR
> >>>> - MALLOC_F_LEN - GBL_DATA_SIZE".
> >>>>
> >>>> But I did it this way to keep it working after Stefan's fix for
> >>>> reserving the boot counter location is applied.
> >>> Now that's confusing :-) Add a comment explaining this into a V2 please,
> >>> otherwise the confusion will continue ...
> >> You're probably right. I'll send a V2 making this more clear.
> > Thanks
>
> Re-checking this, I found the check is still not correct as it would
> leave 4 bytes for the stack only. Is there an option that controls how
> much stack should be preserved for SPL somewhere?

And to make matters worse, the devicetree is also not included in the
size check done by 'arch/arm/cpu/u-boot-spl.lds' unless we select
CONFIG_OF_EMBED.

While this would be OK for SPL, I think it wouldn't be for U-Boot. How
do other platforms handle this size check?


Simon