[U-Boot] [PATCH] board_f: save "malloc_base" from zeroing in case of CONFIG_SYS_MALLOC_F_LEN

Albert ARIBAUD
2015-01-20T07:07:47Z

Hello Alexey,

On Mon, 19 Jan 2015 20:55:03 +0300, Alexey Brodkin
<Alexey.Brodkin@synopsys.com> wrote:
> In case of CONFIG_SYS_MALLOC_F_LEN "malloc_base" is used for early
> start-up code and is set very early, typically in "start.S" or "crt1.S".

There is no "crt1.S" in U-Boot. Did you mean "crt0.S"?

> In current implementation in case of CONFIG_SYS_GENERIC_GLOBAL_DATA all
> global data gets zeroed on "board_init_f" entry. But by that time
> "malloc_base" could have been set already, which means it will be zeroed
> and subsequent C-code will be executed improperly (if executed at all -
> if there's no memory mapped to 0 or it is read-only then on some arches
> there will be an exception and others will quetly die).
>
> To work-around described situation we just need to make sure
> "malloc_base" is saved prior zeroing global data and recovered
> afterwards.

Keeping data from being zeroed etc is usually done through GD. Could
malloc_base be placed there instead of creating a specific exemption
for it?

Amicalement,
--
Albert.