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>
diff --git a/Kconfig b/Kconfig
index 91a0618..b879461 100644
--- a/Kconfig
+++ b/Kconfig
@@ -96,6 +96,24 @@
help
If you want to build SPL as well as the normal image, say Y.
+config SPL_STACK_R
+ depends on SPL
+ bool "Enable SDRAM location for SPL stack"
+ help
+ SPL starts off execution in SRAM and thus typically has only a small
+ stack available. Since SPL sets up DRAM while in its board_init_f()
+ function, it is possible for the stack to move there before
+ board_init_r() is reached. This option enables a special SDRAM
+ location for the SPL stack. U-Boot SPL switches to this after
+ board_init_f() completes, and before board_init_r() starts.
+
+config SPL_STACK_R_ADDR
+ depends on SPL_STACK_R
+ hex "SDRAM location for SPL stack"
+ help
+ Specify the address in SDRAM for the SPL stack. This will be set up
+ before board_init_r() is called.
+
config TPL
bool
depends on SPL && SUPPORT_TPL