@@ -13,34 +13,29 @@ can be reused. No code duplication or symlinking is necessary anymore.
How it works
------------
-There is a new directory $(srctree)/spl which contains only a Makefile.
-The object files are built separately for SPL and placed in this directory.
+The object files for SPL are built separately and placed in the "spl" directory.
The final binaries which are generated are u-boot-spl, u-boot-spl.bin and
u-boot-spl.map.
-During the SPL build a variable named CONFIG_SPL_BUILD is exported
-in the make environment and also appended to CPPFLAGS with -DCONFIG_SPL_BUILD.
+A config option named CONFIG_SPL_BUILD is enabled by Kconfig for SPL.
Source files can therefore be compiled for SPL with different settings.
-ARM-based boards have previously used the option CONFIG_PRELOADER for it.
For example:
ifeq ($(CONFIG_SPL_BUILD),y)
-COBJS-y += board_spl.o
+obj-y += board_spl.o
else
-COBJS-y += board.o
+obj-y += board.o
endif
-COBJS-$(CONFIG_SPL_BUILD) += foo.o
+obj-$(CONFIG_SPL_BUILD) += foo.o
#ifdef CONFIG_SPL_BUILD
foo();
#endif
-The building of SPL images can be with:
-
-#define CONFIG_SPL 1
+The building of SPL images can be enabled by CONFIG_SPL option in Kconfig.
Because SPL images normally have a different text base, one has to be
configured by defining CONFIG_SPL_TEXT_BASE. The linker script has to be
@@ -70,17 +65,6 @@ 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
-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 case CPU will be set to "normal_cpu" during the main u-boot
-build and "spl_cpu" during the SPL build.
-
Debugging
---------
Reflect the latest build system to doc/README.SPL. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> --- doc/README.SPL | 28 ++++++---------------------- 1 file changed, 6 insertions(+), 22 deletions(-)