spl: add overall SPL size check
This adds a size check for SPL that can dynamically check generated
SPL binaries (including devicetree) for a size limit that ensures
this image plus global data, heap and stack fit in initial SRAM.
Since some of these sizes are not available to make, a new host tool
'spl_size_limit' is added that dumps the resulting maximum size for
an SPL binary to stdout. This tool is used in toplevel Makefile to
implement the size check on SPL binaries.
Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index c7cd344..6a98536 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -25,6 +25,42 @@
supports MMC, NAND and YMODEM and other methods loading of U-Boot
and the Linux Kernel. If unsure, say Y.
+config SPL_SIZE_LIMIT
+ hex "Maximum size of SPL image"
+ depends on SPL
+ default 0
+ help
+ Specifies the maximum length of the U-Boot SPL image.
+ If this value is zero, it is ignored.
+
+config SPL_SIZE_LIMIT_SUBTRACT_GD
+ bool "SPL image size check: provide space for global data"
+ depends on SPL_SIZE_LIMIT > 0
+ help
+ If enabled, aligned size of global data is reserved in
+ SPL_SIZE_LIMIT check to ensure such an image does not overflow SRAM
+ if SPL_SIZE_LIMIT describes the size of SRAM available for SPL when
+ pre-reloc global data is put into this SRAM, too.
+
+config SPL_SIZE_LIMIT_SUBTRACT_MALLOC
+ bool "SPL image size check: provide space for malloc() pool before relocation"
+ depends on SPL_SIZE_LIMIT > 0
+ help
+ If enabled, SPL_SYS_MALLOC_F_LEN is reserved in SPL_SIZE_LIMIT check
+ to ensure such an image does not overflow SRAM if SPL_SIZE_LIMIT
+ describes the size of SRAM available for SPL when pre-reloc malloc
+ pool is put into this SRAM, too.
+
+config SPL_SIZE_LIMIT_PROVIDE_STACK
+ hex "SPL image size check: provide stack space before relocation"
+ depends on SPL_SIZE_LIMIT > 0
+ default 0
+ help
+ If set, this size is reserved in SPL_SIZE_LIMIT check to ensure such
+ an image does not overflow SRAM if SPL_SIZE_LIMIT describes the size
+ of SRAM available for SPL when the stack required before reolcation
+ uses this SRAM, too.
+
config HANDOFF
bool "Pass hand-off information from SPL to U-Boot proper"
depends on BLOBLIST