Boot image tools for Samsung Galaxy Tab 4 7.0, Degas board Marvell PXA1088

Unpack boot.img:
$ mkdir boot
$ tools/degas-unpackbootimg -i boot.img -o boot
$ mkdir -p boot/ramdisk
$ cd boot/ramdisk/
$ gunzip -c ../boot.img-ramdisk.gz | cpio -i
$ cd ../

Repack boot.img:
$ ../tools/mkbootfs ramdisk | ../tools/minigzip > boot.img-ramdisk-new.gz
$ ../tools/degas-mkbootimg --kernel boot.img-zImage \
--ramdisk boot.img-ramdisk-new.gz --dt boot.img-dt \
--signature boot.img-signature -o ../boot-new.img
$ cd ../

I'm not sure about boot image signature, you can try without --signature
option. By comparing boot image to recovery image, I found a different
signature and of course a different ramdisk but the rest is the same, including
kernel and device tree table.

To confirm this tools reliability, you can unpack and then repack original
boot/recovery image without modification. You will got two identical image,
check it using a diff tool.

Generate kernel spesific device tree table:
$ tools/degas-dtbTool -o boot.img-dt-new -p kernel/scripts/dtc/ kernel/arch/arm/boot/dts/

Repack a new recovery as a flashable Odin:
$ tar -H ustar -c recovery-testkey.img > recovery-testkey.img.tar
$ md5sum -t recovery-testkey.img.tar >> recovery-testkey.img.tar
$ mv recovery-testkey.img.tar recovery-testkey.img.tar.md5

DISCLAIMER:

USE THIS TOOLS AT YOUR OWN RISK, I DON'T OWN TAB 4 7.0 FOR TESTING

Ketut P. Kumajaya, June 2014