[openwrt/openwrt] ath79: optimize the firmware recipe for Netgear NAND devices

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/3c1512a25d927dbddea96802f55980e6c963302e

commit 3c1512a25d927dbddea96802f55980e6c963302e
Author: Shiji Yang <yangshiji66 at qq.com>
AuthorDate: Tue Nov 29 18:13:38 2022 +0800

    ath79: optimize the firmware recipe for Netgear NAND devices
    
    1. Drop useless character '0xff' before fake filesystem header.
    2. Reduce useless padding to shrink the size of the sysupgrade image.
    3. Do not check the size of sysupgrade image. It does not make sense to
       check the size of a compressed package.
    4. Do not take the size of netgear header into account because it will
       not be written to Flash.
    5. Use the default lzma compression dictionary parameter '-d24' to get
       better performance.
    
    Tested on Netgear R6100
    Signed-off-by: Shiji Yang <yangshiji66 at qq.com>
---
 target/linux/ath79/image/nand.mk | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/target/linux/ath79/image/nand.mk b/target/linux/ath79/image/nand.mk
index 9da47ad38e..ee14c005cc 100644
--- a/target/linux/ath79/image/nand.mk
+++ b/target/linux/ath79/image/nand.mk
@@ -230,7 +230,7 @@ define Device/linksys_ea4500-v3
 endef
 TARGET_DEVICES += linksys_ea4500-v3
 
-# fake rootfs is mandatory, pad-offset 129 equals (2 * uimage_header + 0xff)
+# fake rootfs is mandatory, pad-offset 64 equals (1 * uimage_header)
 define Device/netgear_ath79_nand
   DEVICE_VENDOR := NETGEAR
   DEVICE_PACKAGES := kmod-usb2 kmod-usb-ledtrig-usbport
@@ -238,15 +238,12 @@ define Device/netgear_ath79_nand
   BLOCKSIZE := 128k
   PAGESIZE := 2048
   IMAGE_SIZE := 25600k
-  KERNEL := kernel-bin | append-dtb | lzma -d20 | \
-	pad-offset $$(KERNEL_SIZE) 129 | uImage lzma | \
-	append-string -e '\xff' | \
-	append-uImage-fakehdr filesystem $$(UIMAGE_MAGIC)
-  KERNEL_INITRAMFS := kernel-bin | append-dtb | lzma -d20 | uImage lzma
+  KERNEL := kernel-bin | append-dtb | lzma | uImage lzma | \
+	pad-offset $$(BLOCKSIZE) 64 | append-uImage-fakehdr filesystem $$(UIMAGE_MAGIC)
   IMAGES := sysupgrade.bin factory.img
-  IMAGE/factory.img := append-kernel | append-ubi | netgear-dni | \
-	check-size
-  IMAGE/sysupgrade.bin := sysupgrade-tar | check-size | append-metadata
+  IMAGE/factory.img := append-kernel | pad-to $$$$(KERNEL_SIZE) | \
+	append-ubi | check-size | netgear-dni
+  IMAGE/sysupgrade.bin := sysupgrade-tar | append-metadata
   UBINIZE_OPTS := -E 5
 endef
 
@@ -262,8 +259,7 @@ define Device/netgear_pgzng1
   IMAGE_SIZE := 83968k
   PAGESIZE := 2048
   BLOCKSIZE := 128k
-  KERNEL := kernel-bin | append-dtb | lzma | uImage lzma
-  IMAGE/sysupgrade.bin := sysupgrade-tar | check-size | append-metadata
+  IMAGE/sysupgrade.bin := sysupgrade-tar | append-metadata
 endef
 TARGET_DEVICES += netgear_pgzng1