[openwrt/openwrt] bcm4908: start work on images for devices using U-Boot

[LEDE Commits]

rmilecki pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/a02c971dff934a11ddadf7ffd850dabcab5a3cdf

commit a02c971dff934a11ddadf7ffd850dabcab5a3cdf
Author: Rafał Miłecki <rafal at milecki.pl>
AuthorDate: Wed Nov 3 18:12:05 2021 +0100

    bcm4908: start work on images for devices using U-Boot
    
    New BCM4908 family based routers will use U-Boot bootloader. That will
    require using a totally different firmware format. Kernel has to be put
    in a FIT image.
    
    OpenWrt has some helpers for generating .its files but they don't fit
    BCM4908 requirements and there is no simple way of extending any of
    them. The best solution seems to be storing an .its template.
    
    BCM4908 bootfs may:
    1. contain extra binaries (other than kernel & DTB)
    2. include multiple DTB files
    3. store device specific U-Boot configurations with custom properties
    
    Such setups are too complex to generate using shell script. Raw .its
    file on the other hand seems quire clean & reasonable.
    
    Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
 target/linux/bcm4908/image/Makefile           | 11 +++++++++++
 target/linux/bcm4908/image/bootfs-generic.its | 25 +++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/target/linux/bcm4908/image/Makefile b/target/linux/bcm4908/image/Makefile
index 426db4c5a6..929e626e0e 100644
--- a/target/linux/bcm4908/image/Makefile
+++ b/target/linux/bcm4908/image/Makefile
@@ -6,6 +6,17 @@ include $(INCLUDE_DIR)/image.mk
 DEVICE_VARS += ASUS_PRODUCTID ASUS_BUILD_NO ASUS_FW_REV ASUS_EXT_NO
 DEVICE_VARS += NETGEAR_BOARD_ID NETGEAR_REGION
 
+define Image/Prepare
+	cp bootfs-generic.its $(KDIR)/
+endef
+
+define Build/bootfs
+	cat $@ | $(STAGING_DIR_HOST)/bin/lzma e -eos -si -so > $@.tmp
+	mv $@.tmp $@
+	sed -i "s=\$${kernel}=$@=" $(KDIR)/bootfs-generic.its
+	PATH=$(LINUX_DIR)/scripts/dtc:$(PATH) mkimage -f $(KDIR)/bootfs-generic.its $(KDIR)/bootfs-generic.itb
+endef
+
 define Build/bcm4908asus
 	$(STAGING_DIR_HOST)/bin/bcm4908asus create -i $@ \
 		-p $(ASUS_PRODUCTID) -b $(ASUS_BUILD_NO) -f $(ASUS_FW_REV) \
diff --git a/target/linux/bcm4908/image/bootfs-generic.its b/target/linux/bcm4908/image/bootfs-generic.its
new file mode 100644
index 0000000000..d2f19ed752
--- /dev/null
+++ b/target/linux/bcm4908/image/bootfs-generic.its
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+/dts-v1/;
+
+/ {
+	description = "OpenWrt bootfs image";
+	#address-cells = <1>;
+
+	images {
+		kernel {
+			description = "Linux kernel";
+			data = /incbin/("${kernel}");
+			type = "kernel";
+			os = "linux";
+			arch = "arm64";
+			compression = "lzma";
+			load = <0x80000>;
+			entry = <0x80000>;
+
+			hash-1 {
+				algo = "sha256";
+			};
+		};
+	};
+};