Hi Jonas,

On Sat, 8 Aug 2026 at 14:45, Jonas Karlman <[email protected]> wrote:
>
> Hi Simon,
>
> On 8/8/2026 3:52 PM, Simon Glass wrote:
> > Hi Jonas,
> >
> > On Fri, 7 Aug 2026 at 17:06, Jonas Karlman <[email protected]> wrote:
> >>
> >> Hi Simon,
> >>
> >> On 8/8/2026 12:00 AM, Simon Glass wrote:
> >>> Hi Jonas,
> >>>
> >>> On Fri, 7 Aug 2026 at 15:41, Jonas Karlman <[email protected]> wrote:
> >>>>
> >>>> Hi Simon,
> >>>>
> >>>> On 8/7/2026 10:40 PM, Simon Glass wrote:
> >>>>> Hi Jonas,
> >>>>>
> >>>>> On 2026-08-07T09:04:31, Jonas Karlman <[email protected]> wrote:
> >>>>>> rockchip: px30: Fix TPL_STACK overflow into BootROM reserved region
> >>>>>>
> >>>>>> The PX30/RK3326 has 16 KiB SRAM at [0xff0e0000, 0xff0e4000), with the
> >>>>>> initial 4 KiB at [0xff0e0000, 0xff0e1000) reserved for BootROM at boot.
> >>>>>>
> >>>>>> SRAM addressing only seem to use 14 bits, meaning that reading from
> >>>>>> 0xff0e4000+ wraps around and instad reads back data at 0xff0e0000+.
> >>>>>
> >>>>> Typos: 'seem' -> 'seems', 'instad' -> 'instead' and 'possible looks'
> >>>>> below -> 'possibly looks'.
> >>>>
> >>>> Thanks, will update in a v2.
> >>>>
> >>>>>
> >>>>>>
> >>>>>> Using a TPL_STACK at 0xff0e4ff0 (16-bytes aligned) means TPL use 
> >>>>>> BootROM
> >>>>>> reserved region for its global data, malloc area and runtime stack.
> >>>>>>
> >>>>>> TPL on PX30/RK3326 does not have any use for the malloc area and the
> >>>>>> generated GD_SIZE is typically around 304 bytes.
> >>>>>>
> >>>>>> Current memory layout possible looks something like:
> >>>>>>
> >>>>>>   [0xff0e0000, 0xff0e4000)          16 KiB   SRAM
> >>>>>>     [0xff0e0000, 0xff0e1000)         4 KiB   BROM area
> >>>>>>       [0xff0e09f0, 0xff0e0ff0)    1536 bytes  malloc area (unused)
> >>>>>>       [0xff0e08c0, 0xff0e09f0)     304 bytes  global data
> >>>>>> [...]
> >>>>>>
> >>>>>> arch/arm/mach-rockchip/px30/Kconfig | 4 ++--
> >>>>>>  common/spl/Kconfig.tpl              | 2 +-
> >>>>>>  tools/rkcommon.c                    | 2 +-
> >>>>>>  3 files changed, 4 insertions(+), 4 deletions(-)
> >>>>>
> >>>>>> diff --git a/common/spl/Kconfig.tpl b/common/spl/Kconfig.tpl
> >>>>>> @@ -129,7 +129,7 @@ config TPL_MAX_SIZE
> >>>>>> -     default 0x2800 if ROCKCHIP_PX30
> >>>>>> +     default 0x2c00 if ROCKCHIP_PX30
> >>>>>
> >>>>> Just to check, the layout shows [0xff0e3c00, 0xff0e3ed0) as pure
> >>>>> stack, but BSS (e.g. dram_info in sdram_px30.c) sits after
> >>>>> __image_copy_end and is not counted by the TPL_MAX_SIZE assert in
> >>>>> u-boot-tpl-v8.lds, so with an image close to 11 KiB the real stack
> >>>>> headroom is a bit less than 720 bytes.
> >>>>
> >>>> You are correct, current BSS is 72 bytes, will update the commit message
> >>>> to mention that the 720 bytes must fit both BSS and the stack in a v2.
> >>>>
> >>>> What is interesting is that global data is so large, especially when in
> >>>> this case nothing here is really using global data. We could save 16
> >>>> bytes by fully disable CONFIG_TPL_SYS_MALLOC_F, but that was too
> >>>> intrusive to be part of this fix.
> >>>
> >>> Well we have DRAM in there now. Actually now that Ilas' series is in,
> >>> we could take a look at trimming and aligning things - some things are
> >>> long which could be int, which matters on arm64.
> >>
> >> The px30/rk3326 boards do use CONFIG_NR_DRAM_BANKS=1 or 2, so dram
> >> should at least be limited somewhat.
> >>
> >> I think there are some DM related fields that could be excluded to save
> >> little bit more space. With below diff the GD_SIZE is down to 240 bytes,
> >> 16 for TPL_SYS_MALLOC_F and remaining 48 due to the DM related fields.
> >> Not sure this is safe, but the odroid-go2_defconfig could be built.
> >>
> >> I do not think the global data size is really a big issue for this
> >> board, but rk3036 only have 4 KiB that need to fit SPL (2716b),
> >> BSS (0b), global data (160b) and stack. SPL image is down to 2716 bytes
> >> after upcoming TPL refactoring at [1] (tpl branch).
> >>
> >> diff --git a/configs/odroid-go2_defconfig b/configs/odroid-go2_defconfig
> >> index dfdea66cd70c..c5fd6514010c 100644
> >> --- a/configs/odroid-go2_defconfig
> >> +++ b/configs/odroid-go2_defconfig
> >> @@ -118,3 +118,4 @@ CONFIG_USB_FUNCTION_ROCKUSB=y
> >>  CONFIG_TPL_TINY_MEMSET=y
> >>  CONFIG_LZO=y
> >>  CONFIG_ERRNO_STR=y
> >> +# CONFIG_TPL_SYS_MALLOC_F is not set
> >> diff --git a/include/asm-generic/global_data.h 
> >> b/include/asm-generic/global_data.h
> >> index fd116b0cebf2..886c12900ddb 100644
> >> --- a/include/asm-generic/global_data.h
> >> +++ b/include/asm-generic/global_data.h
> >> @@ -174,10 +174,12 @@ struct global_data {
> >>          * @arch: architecture-specific data
> >>          */
> >>         struct arch_global_data arch;
> >> +#if CONFIG_IS_ENABLED(DM)
> >>         /**
> >>          * @dmtag_list: List of DM tags
> >>          */
> >>         struct list_head dmtag_list;
> >> +#endif
> >>         /**
> >>          * @timebase_h: high 32 bits of timer
> >>          */
> >> @@ -228,7 +230,7 @@ struct global_data {
> >>          */
> >>         long precon_buf_idx;
> >>  #endif
> >> -#ifdef CONFIG_DM
> >> +#if CONFIG_IS_ENABLED(DM)
> >>         /**
> >>          * @dm_root: root instance for Driver Model
> >>          */
> >
> > Yes please, that's a huge improvement!
>
> Will send out above struct global_data in a separate patch, CI seem to
> pass with above changes applied, see [2].

OK good. Ilias may have some comment too.

Regards,
Simon


>
> [2] 
> https://git.u-boot-project.org/u-boot/contributors/kwiboo/u-boot/-/pipelines/924
>
> Regards,
> Jonas
>
> >
> >>
> >> [1] 
> >> https://git.u-boot-project.org/u-boot/contributors/kwiboo/u-boot/-/commit/8c8b98a29aa35880b93bbacce8daf68edb537eca
> >>
> >> Regards,
> >> Jonas
> >>
> >>>
> >>> I also did some work on struct board_f which is another way to reduce
> >>> space, if we can find more things which are only needed in early board
> >>> start-up. I suppose we could even expand that to include the
> >>> board_init_r() calls.
> >>>
> >>> Regards,
> >>> Simon
> >>
> >
> > Regards,
> > Simon
>

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