Re: [PATCH] board_f: Call initf_malloc() before fdtdec_setup()

Hi Marek,

On Tue, 21 Jul 2026 at 13:48, Marek Vasut
<[email protected]> wrote:
>
> In case MULTI_DTB_FIT_GZIP is enabled, fdtdec_setup() does uncompress
> the compressed DTs in uncompress_blob() using gunzip(), which invokes
> malloc() internally. The early simple malloc is initialized in board_f
> initf_malloc() call, which sets up the early simple malloc limit and
> offset pointer in global data. Currently, the initf_malloc() is called
> after fdtdec_setup(), which leads to malloc failure in fdtdec_setup()
> during the gzip decompression, because the early simple malloc is not
> initialized yet.
>
> Call initf_malloc() before fdtdec_setup() to assure fdtdec_setup() can
> use malloc() during gzip decompression of the DTs.
>
> The impact of this change on boot time is negligible, because the
> initf_malloc() only assigns two fields in global data.
>
> Signed-off-by: Marek Vasut <[email protected]>
> ---
> Cc: Ilias Apalodimas <[email protected]>
> Cc: Simon Glass <[email protected]>
> Cc: Tom Rini <[email protected]>
> Cc: [email protected]
> ---
>  common/board_f.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

I'm not keen on reordering this list...

The offending call is inside uncompress_blob(), which already has a
non-malloc path - MULTI_DTB_FIT_USER_DEFINED_AREA with
MULTI_DTB_FIT_USER_DEF_ADDR. That is the pattern most boards using
compressed multi-DTB FIT already use, and it avoids early malloc
altogether. Could the BTT config not just switch to that and drop the
board-local initf_malloc() workaround at the same time?

Failing that, the per-board workaround in board/liebherr/btt/btt.c is
ugly but localised. If we really want a generic fix, I would rather
see uncompress_blob() call initf_malloc() itself when it needs the
heap, so the ordering constraint stays local to the code that needs
it. We would need to ensure that malloc() isn't then inited a second
time. We could always add a flag to gd->boardf, I suppose.

The reordering also means that malloc cannot be traced - the idea with
trace is that it is enabled as early as possible. Finally (that I can
think of), it means that early malloc can never be configured by the
devicetree (although that is not something we have needed yet).

Regards,
Simon