ath79: lzma-loader: allow setting custom kernel magic

...and max flash offset

The mtdsplit parser was recently refactored
to allow the kernel to have custom image header magic.

Let's also do this for the lzma-loader

For example:
When implemented together,
this allows the kernel to "appear" to be a rootfs
by OEM software in order to write an image
that is actually kernel + rootfs.

At the same time,
it would boot to openwrt normally
by setting the same magic in DTS.

Both of the variables
have a default value that is unchanged
when not defined in the makefiles

This has no effect on the size of the loader
when lzma compressed.

Signed-off-by: Michael Pratt <mcpratt@pm.me>

diff --git a/target/linux/ath79/image/Makefile b/target/linux/ath79/image/Makefile
index c2d2474336bd6288d3babd9dc2a8d021f72d992e..d8b8800d91dfe332c90a9ddc695ce24af3a27676 100644 (file)
--- a/target/linux/ath79/image/Makefile
+++ b/target/linux/ath79/image/Makefile
@@ -4,6 +4,7 @@ include $(INCLUDE_DIR)/image.mk
 KERNEL_LOADADDR = 0x80060000
 
 DEVICE_VARS += LOADER_FLASH_OFFS LOADER_TYPE
+DEVICE_VARS += LOADER_FLASH_MAX LOADER_KERNEL_MAGIC
 DEVICE_VARS += NETGEAR_BOARD_ID NETGEAR_HW_ID
 DEVICE_VARS += RAS_BOARD RAS_ROOTFS_SIZE RAS_VERSION
 
@@ -30,7 +31,10 @@ define Build/loader-kernel
 endef
 
 define Build/loader-okli-compile
-       $(call Build/loader-common,FLASH_OFFS=$(LOADER_FLASH_OFFS) FLASH_MAX=0)
+       $(call Build/loader-common, \
+               FLASH_OFFS=$(LOADER_FLASH_OFFS) \
+               FLASH_MAX=$(LOADER_FLASH_MAX) \
+               KERNEL_MAGIC=$(LOADER_KERNEL_MAGIC) )
 endef
 
 # Arguments: <output name> <kernel offset>

diff --git a/target/linux/ath79/image/lzma-loader/Makefile b/target/linux/ath79/image/lzma-loader/Makefile
index 0ff59bc56a8c7275725347a85eb8fb95593f9c76..2b1ed82a989c64e6fa8996afa416f1aae17c8796 100644 (file)
--- a/target/linux/ath79/image/lzma-loader/Makefile
+++ b/target/linux/ath79/image/lzma-loader/Makefile
@@ -13,6 +13,7 @@ LOADADDR      := 0x80060000
 LOADER         := loader.bin
 LOADER_NAME    := $(basename $(notdir $(LOADER)))
 LOADER_DATA    :=
+KERNEL_MAGIC   :=
 TARGET_DIR     :=
 FLASH_OFFS     :=
 FLASH_MAX      :=
@@ -41,6 +42,7 @@ loader-compile: $(PKG_BUILD_DIR)/.prepared
                LZMA_TEXT_START=$(LZMA_TEXT_START) \
                LOADADDR=$(LOADADDR) \
                LOADER_DATA=$(LOADER_DATA) \
+               KERNEL_MAGIC=$(KERNEL_MAGIC) \
                FLASH_OFFS=$(FLASH_OFFS) \
                FLASH_MAX=$(FLASH_MAX) \
                BOARD="$(BOARD)" \

diff --git a/target/linux/ath79/image/lzma-loader/src/Makefile b/target/linux/ath79/image/lzma-loader/src/Makefile
index 7773f027a24975bb7204b1dec141e3bd39092874..c7bb935a030ccffb0bb45eb7a6cbc647e360a76e 100644 (file)
--- a/target/linux/ath79/image/lzma-loader/src/Makefile
+++ b/target/linux/ath79/image/lzma-loader/src/Makefile
@@ -18,6 +18,7 @@
 LOADADDR       :=
 LZMA_TEXT_START        := 0x80a00000
 LOADER_DATA    :=
+KERNEL_MAGIC   :=
 BOARD          :=
 FLASH_OFFS     :=
 FLASH_MAX      :=
@@ -54,6 +55,10 @@ OBJECTS              += data.o
 CFLAGS         += -DLZMA_WRAPPER=1 -DLOADADDR=$(LOADADDR)
 endif
 
+ifneq ($(strip $(KERNEL_MAGIC)),)
+CFLAGS         += -DCONFIG_KERNEL_MAGIC=$(KERNEL_MAGIC)
+endif
+
 ifneq ($(strip $(KERNEL_CMDLINE)),)
 CFLAGS         += -DCONFIG_KERNEL_CMDLINE='"$(KERNEL_CMDLINE)"'
 endif

diff --git a/target/linux/ath79/image/lzma-loader/src/loader.c b/target/linux/ath79/image/lzma-loader/src/loader.c
index 794c4b6285a7fa0423c22d172828415e6f2be93b..0213e9457423da4c467c1dbb856dc0cf1afbef0e 100644 (file)
--- a/target/linux/ath79/image/lzma-loader/src/loader.c
+++ b/target/linux/ath79/image/lzma-loader/src/loader.c
@@ -189,7 +189,11 @@ static void lzma_init_data(void)
 
                p = flash_base + flash_ofs;
                magic = get_be32(p);
+#ifdef CONFIG_KERNEL_MAGIC
+               if (magic == CONFIG_KERNEL_MAGIC) {
+#else
                if (magic == IH_MAGIC_OKLI) {
+#endif
                        hdr = (struct image_header *) p;
                        break;
                }