[U-Boot] [PATCH] mkconfig: add support for SPL CPU

[Allen Martin]

Add support for specifying a differnt CPU for main u-boot and SPL
u-boot builds.  This is done by adding an optional SPL CPU after the
main 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
build and "spl_cpu" during the SPL build.

Signed-off-by: Allen Martin <amartin at nvidia.com>
---
This is part of my patch series to move all armv4t code out of tegra
u-boot to an SPL.  I haven't heard any suggestions on how to resolve
having a different CPU for the SPL build, so this is my suggestion
as a possible solution.

 boards.cfg     |    5 +++++
 doc/README.SPL |   12 ++++++++++++
 mkconfig       |   15 ++++++++++++++-
 3 files changed, 31 insertions(+), 1 deletions(-)

diff --git a/boards.cfg b/boards.cfg
index 3cf75c3..a58cd02 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -11,6 +11,11 @@
 #	Lines starting with '#' are comments.
 #	Blank lines are ignored.
 #
+#	The CPU field takes the form:
+#		cpu[:spl_cpu]
+#	If spl_cpu is specified the make variable CPU will be set to this
+#	during the SPL build.
+#
 #	The options field takes the form:
 #		<board config name>[:comma separated config options]
 #	Each config option has the form (value defaults to "1"):
diff --git a/doc/README.SPL b/doc/README.SPL
index 0276953..e4a5ac3 100644
--- a/doc/README.SPL
+++ b/doc/README.SPL
@@ -66,3 +66,15 @@ 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)
+
+
+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
+the SPL build for cases where the SPL is expected to run on a
+different CPU model from the main u-boot.  This is done by specifying
+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
+build and "spl_cpu" during the SPL build.
diff --git a/mkconfig b/mkconfig
index 438530b..82660a6 100755
--- a/mkconfig
+++ b/mkconfig
@@ -60,6 +60,11 @@ CONFIG_NAME="${1%_config}"
 
 arch="$2"
 cpu="$3"
+tmp="${cpu#*:}"
+if [ "$tmp" != "$cpu" ] ; then
+	spl_cpu=$tmp
+	cpu="${cpu%:*}"
+fi
 if [ "$4" = "-" ] ; then
 	board=${BOARD_NAME}
 else
@@ -131,7 +136,15 @@ fi
 # Create include file for Make
 #
 echo "ARCH   = ${arch}"  >  config.mk
-echo "CPU    = ${cpu}"   >> config.mk
+if [ ! -z "$spl_cpu" ] ; then
+	echo 'ifeq ($(CONFIG_SPL_BUILD),y)' >> config.mk
+	echo "CPU    = ${spl_cpu}" >> config.mk
+	echo "else" >> config.mk
+	echo "CPU    = ${cpu}"   >> config.mk
+	echo "endif" >> config.mk
+else
+	echo "CPU    = ${cpu}"   >> config.mk
+fi
 echo "BOARD  = ${board}" >> config.mk
 
 [ "${vendor}" ] && echo "VENDOR = ${vendor}" >> config.mk
-- 
1.7.5.4