Extracting the values of some fields in setup.bin
setup.bin contains the structure defined in
arch/x86/boot/header.S. Some values of these structure can be read with the following shell script:
file=arch/x86/boot/setup.bin
# file=arch/x86/boot/bzImage
echo "setup_sects: $(od --skip-bytes=497 --read-bytes=1 --format=x1 --address-radix=n $file)"
echo "syssize: $(od --skip-bytes=500 --read-bytes=4 --format=d --address-radix=n $file)"
echo "rootdev: $(od --skip-bytes=508 --read-bytes=2 --format=d --address-radix=n $file)"
echo "boot_flag: $(od --skip-bytes=510 --read-bytes=2 --format=x2 --address-radix=n $file)" # expected aa55
echo "jump: $(od --skip-bytes=512 --read-bytes=1 --format=x1 --address-radix=n $file)" # expected eb (Assembler JMP instruction)
echo "header: $(dd if=$file bs=1 skip=514 count=5 2>/dev/null )" # expected HdRS
echo "version: $(od --skip-bytes=518 --read-bytes=2 --format=x2 --address-radix=n $file)"
echo "handover_offset: $(od --skip-bytes=612 --read-bytes=4 --format=x4 --address-radix=n $file)"
echo "kernel_invo_offset: $(od --skip-bytes=616 --read-bytes=4 --format=x4 --address-radix=n $file)"