/* head.s is loaded at 0x1000 (by second stage), its main goal is run 32-bit startup code. After that manipulations it jumps to kernel written by C */ .code32 # Tell GAS to generate 32 bit code .extern kernel_main .set CODESEG, 0x08 .set DATASEG, 0x10 .global _start _start: mov $DATASEG, %ax # Point segment registers to the mov %ax, %ds # data selector we defined in our GDT mov %ax, %es mov %ax, %ss mov %ax, %fs mov %ax, %gs mov $0x90000, %ebp # Update stack position so it is right mov %ebp, %esp # at the top of the free space. call kernel_main jmp . # infinite loop