X-Git-Url: https://git.kernelconcepts.de/?a=blobdiff_plain;f=doc%2FREADME.SPL;h=57a39a489b9afe74249a97afc0be2decfd2bcde6;hb=ae7f4513087e7f7996cebc9db642917dde9ea561;hp=bd375a01d96d19431af4bb4cfa2142d43834ce8b;hpb=f8e754d51cd9573e22eecea8543bcceffe313e95;p=karo-tx-uboot.git

diff --git a/doc/README.SPL b/doc/README.SPL
index bd375a01d9..57a39a489b 100644
--- a/doc/README.SPL
+++ b/doc/README.SPL
@@ -13,7 +13,7 @@ can be reused. No code duplication or symlinking is necessary anymore.
 How it works
 ------------
 
-There is a new directory TOPDIR/spl which contains only a Makefile.
+There is a new directory $(srctree)/spl which contains only a Makefile.
 The object files are built separately for SPL and placed in this directory.
 The final binaries which are generated are u-boot-spl, u-boot-spl.bin and
 u-boot-spl.map.
@@ -62,11 +62,13 @@ CONFIG_SPL_FAT_SUPPORT (fs/fat/libfat.o)
 CONFIG_SPL_LIBGENERIC_SUPPORT (lib/libgeneric.o)
 CONFIG_SPL_POWER_SUPPORT (drivers/power/libpower.o)
 CONFIG_SPL_NAND_SUPPORT (drivers/mtd/nand/libnand.o)
+CONFIG_SPL_DRIVERS_MISC_SUPPORT (drivers/misc)
 CONFIG_SPL_DMA_SUPPORT (drivers/dma/libdma.o)
 CONFIG_SPL_POST_MEM_SUPPORT (post/drivers/memory.o)
 CONFIG_SPL_NAND_LOAD (drivers/mtd/nand/nand_spl_load.o)
 CONFIG_SPL_SPI_LOAD (drivers/mtd/spi/spi_spl_load.o)
-
+CONFIG_SPL_RAM_DEVICE (common/spl/spl.c)
+CONFIG_SPL_WATCHDOG_SUPPORT (drivers/watchdog/libwatchdog.o)
 
 Normally CPU is assumed to be the same between the SPL and normal
 u-boot build.  However it is possible to specify a different CPU for
@@ -76,7 +78,7 @@ an SPL CPU in boards.cfg as follows:
 
 	normal_cpu:spl_cpu
 
-This this case CPU will be set to "normal_cpu" during the main u-boot
+This case CPU will be set to "normal_cpu" during the main u-boot
 build and "spl_cpu" during the SPL build.
 
 
@@ -85,3 +87,26 @@ Debugging
 
 When building SPL with DEBUG set you may also need to set CONFIG_PANIC_HANG
 as in most cases do_reset is not defined within SPL.
+
+
+Estimating stack usage
+----------------------
+
+With gcc 4.6 (and later) and the use of GNU cflow it is possible to estimate
+stack usage at various points in run sequence of SPL.  The -fstack-usage option
+to gcc will produce '.su' files (such as arch/arm/cpu/armv7/syslib.su) that
+will give stack usage information and cflow can construct program flow.
+
+Must have gcc 4.6 or later, which supports -fstack-usage
+
+1) Build normally
+2) Perform the following shell command to generate a list of C files used in
+SPL:
+$ find spl -name '*.su' | sed -e 's:^spl/::' -e 's:[.]su$:.c:' > used-spl.list
+3) Execute cflow:
+$ cflow --main=board_init_r `cat used-spl.list` 2>&1 | $PAGER
+
+cflow will spit out a number of warnings as it does not parse
+the config files and picks functions based on #ifdef.  Parsing the '.i'
+files instead introduces another set of headaches.  These warnings are
+not usually important to understanding the flow, however.