Gujin: Difference between revisions

Then, we reformat that dedicated USB stick as a bootable FAT filesystem, erasing all its content: first go in "root" by typing "su" or "sudo" (distribution dependant), then get the device name of you USB stick (let's say it is /dev/sdg) (sometimes /dev/mmcblk0 for SD cards), and type:

./gujin /dev/sdg --disk=BIOS:0x00,auto

Depending on the size of the USB stick, that will have created either a FAT16 or a FAT32 (or even a FAT12) filesystem, but that point is not really important.

To check that this filesystem is correctly created, you can type:

/sbin/fsck.vfat /dev/sdg

With the Gujin installer parameters we used, that would have created a "superfloppy" format on our USB stick, that is currently the format most PC will be able to understand and boot from.

Then compile it like (you may need to add "-fno-stack-protector" too, distribution dependant):

gcc -m32 -Wall -O2 -s -static -nostartfiles -nodefaultlibs -Wl,-Ttext=0x110000 hello.c -o hello.elf

and compress it by:

gzip -9 hello.elf -c > hello.kgz

You just need to copy that hello.kgz file into the USB stick, and reboot with this USB stick, you will get a menu with "hello.kgz" displayed.

And then compile it by:

gcc -m32 -Wall -Os -s -static -nostartfiles -nodefaultlibs -Wa,-R -Wl,--section-start,.init=0 hello_bios.c -o hello_bios.elf

and compress it:

gzip -9 hello_bios.elf -c > hello_bios.kgz

you can copy this hello_bios.kgz to the USB stick and run it, I hope the different functions of the source file are obvious.