[PATCH u-boot-marvell 08/16] arm: mvebu: Correctly set LOAD_ADDRESS for U-Boot SPL binary in kwbimage

Pali Rohár
2021-12-21T15:57:48Z

U-Boot SPL for mvebu platform is not compiled as position independent.
Therefore it is required to instruct BootROM to load U-Boot SPL at the
correct address. Loading of kwbimage binary code at specific address can be
now achieved by the new LOAD_ADDRESS token as part of BINARY command in
kwbimage config file.

Update mvebu Makefile to put value of $(CONFIG_SPL_TEXT_BASE) into
LOAD_ADDRESS token when generating kwbimage.cfg from kwbimage.cfg.in.

It is required to update regex for sed to find replacement tokens at any
position on a line in kwbimage config file and not only at the beginning of
the line. This is because LOAD_ADDRESS is specified at the end of line
containing the BINARY command.

It looks like all Armada boards set CONFIG_SPL_TEXT_BASE to value
0x40000030. Why this value? It is because main kwbimage header is at
address 0x40000000 and it is 32 bytes long. After the main header there is
the binary header, which consist of 1 byte for type, 3 bytes for size, 1
byte for number of arguments, 3 reserved bytes and then 4 bytes for each
argument. After these arguments comes the executable code.

So arguments start at address 0x40000028. Before commit e6571f38c943 ("arm:
mvebu: Remove dummy BIN header arguments for SPL binary") there were two
(dummy) arguments, which resulted in load address of 0x40000030, always.
After that commit (which removed dummy arguments), load address stayed same
due to the 128-bit alignment done by mkimage.

This patch now reflects the dependency between $(CONFIG_SPL_TEXT_BASE),
load address and dummy kwbimage arguments, and allows the user to adjust
$(CONFIG_SPL_TEXT_BASE) config option to some other value.

For unsupported values, when mkimage/kwbimage cannot set chosen load address
as specified by $(CONFIG_SPL_TEXT_BASE), the build process now fails,
instead of silently generating non-working kwbimage.

Removal of this alignment between $(CONFIG_SPL_TEXT_BASE) and LOAD_ADDRESS
can only be done by compiling U-Boot SPL as position independent. But this
currently is not possible for 32-bit ARM version of U-Boot SPL.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
---
arch/arm/mach-mvebu/Makefile | 5 ++++-
arch/arm/mach-mvebu/kwbimage.cfg.in | 4 ++--
2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index acbaa6449d3d..0fc638086ee5 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile
@@ -30,6 +30,9 @@ obj-$(CONFIG_MVEBU_EFUSE) += efuse.o

extra-y += kwbimage.cfg

+KWB_REPLACE += LOAD_ADDRESS
+KWB_CFG_LOAD_ADDRESS = $(CONFIG_SPL_TEXT_BASE)
+
KWB_REPLACE += BOOT_FROM
ifneq ($(CONFIG_MVEBU_SPL_BOOT_DEVICE_SPI),)
KWB_CFG_BOOT_FROM=spi
@@ -59,7 +62,7 @@ KWB_CFG_SEC_FUSE_DUMP = a38x
endif

quiet_cmd_kwbcfg = KWBCFG $@
-cmd_kwbcfg = sed -ne '$(foreach V,$(KWB_REPLACE),s/^\#@$(V)/$(V) $(KWB_CFG_$(V))/;)p' \
+cmd_kwbcfg = sed -ne '$(foreach V,$(KWB_REPLACE),s/\#@$(V)/$(V) $(KWB_CFG_$(V))/;)p' \
<$< >$(dir $@)$(@F)

$(obj)/kwbimage.cfg: $(src)/kwbimage.cfg.in include/autoconf.mk \
diff --git a/arch/arm/mach-mvebu/kwbimage.cfg.in b/arch/arm/mach-mvebu/kwbimage.cfg.in
index 049d23c6ef08..2791c21617b3 100644
--- a/arch/arm/mach-mvebu/kwbimage.cfg.in
+++ b/arch/arm/mach-mvebu/kwbimage.cfg.in
@@ -8,5 +8,5 @@ VERSION 1
# Boot Media configurations
#@BOOT_FROM

-# Binary Header (bin_hdr) with DDR3 training code
-BINARY spl/u-boot-spl.bin
+# Include U-Boot SPL with DDR3 training code into Binary Header
+BINARY spl/u-boot-spl.bin #@LOAD_ADDRESS
--
2.20.1