diff options
author | Simon Glass <sjg@chromium.org> | 2015-03-03 18:03:00 +0300 |
---|---|---|
committer | Tom Rini <trini@konsulko.com> | 2015-03-04 22:55:04 +0300 |
commit | db910353a126d84fe8dff7a694ea792f50fcfb6a (patch) | |
tree | 0cca558754e992284820fbc240690c13d0a00cb0 /common | |
parent | bdfb34167f73afc7e04d52499fc14bc1cd33fec0 (diff) | |
download | u-boot-db910353a126d84fe8dff7a694ea792f50fcfb6a.tar.xz |
arm: spl: Allow board_init_r() to run with a larger stack
At present SPL uses a single stack, either CONFIG_SPL_STACK or
CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and
environment) require a lot of stack, some boards set CONFIG_SPL_STACK to
point into SDRAM. They then set up SDRAM very early, before board_init_f(),
so that the larger stack can be used.
This is an abuse of lowlevel_init(). That function should only be used for
essential start-up code which cannot be delayed. An example of a valid use is
when only part of the SPL code is visible/executable, and the SoC must be set
up so that board_init_f() can be reached. It should not be used for SDRAM
init, console init, etc.
Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new
address before board_init_r() is called in SPL.
The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README.
Signed-off-by: Simon Glass <sjg@chromium.org>
For version 1:
Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Heiko Schocher <hs@denx.de>
Tested-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'common')
-rw-r--r-- | common/spl/spl.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/common/spl/spl.c b/common/spl/spl.c index ded0f30478..cd75bbc4ce 100644 --- a/common/spl/spl.c +++ b/common/spl/spl.c @@ -281,3 +281,38 @@ void preloader_console_init(void) spl_display_print(); #endif } + +/** + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution + * + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM + * for the main board_init_r() execution. This is typically because we need + * more stack space for things like the MMC sub-system. + * + * This function calculates the stack position, copies the global_data into + * place and returns the new stack position. The caller is responsible for + * setting up the sp register. + * + * @return new stack location, or 0 to use the same stack + */ +ulong spl_relocate_stack_gd(void) +{ +#ifdef CONFIG_SPL_STACK_R + gd_t *new_gd; + ulong ptr; + + /* Get stack position: use 8-byte alignment for ABI compliance */ + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); + ptr &= ~7; + new_gd = (gd_t *)ptr; + memcpy(new_gd, (void *)gd, sizeof(gd_t)); + gd = new_gd; + + /* Clear the BSS. */ + memset(__bss_start, 0, __bss_end - __bss_start); + + return ptr; +#else + return 0; +#endif +} |