Hi Alexey,
On 19 January 2015 at 10:55, 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".
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.
Signed-off-by: Alexey Brodkin abrodkin@synopsys.com Cc: Wolfgang Denk wd@denx.de Cc: Simon Glass sjg@chromium.org Cc: Tom Rini trini@ti.com Cc: Masahiro Yamada yamada.m@jp.panasonic.com
common/board_f.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/common/board_f.c b/common/board_f.c index 3a4b32c..ebdba0e 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -999,6 +999,9 @@ static init_fnc_t init_sequence_f[] = { void board_init_f(ulong boot_flags) { #ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA +#ifdef CONFIG_SYS_MALLOC_F_LEN
int malloc_base;+#endif /* * For some archtectures, global data is initialized and used before * calling this function. The data should be preserved. For others, @@ -1009,12 +1012,25 @@ void board_init_f(ulong boot_flags)
gd = &data;+#ifdef CONFIG_SYS_MALLOC_F_LEN
/** "malloc_base" is supposed to be set in the very beginning of start-up* code (start.S or crt0.S), now we need to preserve it from zeroing.*/malloc_base = gd->malloc_base;+#endif
/* * Clear global data before it is accessed at debug print * in initcall_run_list. Otherwise the debug print probably * get the wrong vaule of gd->have_console. */ zero_global_data();+#ifdef CONFIG_SYS_MALLOC_F_LEN
/* Restore "malloc_base" value */gd->malloc_base = malloc_base;+#endif #endif
gd->flags = boot_flags;-- 2.1.0
CONFIG_SYS_GENERIC_GLOBAL_DATA seems to be mis-named, but in any case it must not be used with CONFIG_SYS_MALLOC_F_LEN. We are trying to get rid of all these cases of multiple global_data structures. It should be set up in start.S and not anywhere else.
Better would be:
#ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA +#ifdef CONFIG_SYS_MALLOC_F_LEN +#error "CONFIG_SYS_GENERIC_GLOBAL_DATA is deprecated - please remove use of this if you want to use early malloc() +#endif
Regards, Simon