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,