diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S index 2e55923..17e6dec 100644 --- a/arch/x86/boot/pmjump.S +++ b/arch/x86/boot/pmjump.S @@ -28,27 +28,37 @@ * void protected_mode_jump(u32 entrypoint, u32 bootparams); */ protected_mode_jump: - xorl %ebx, %ebx # Flag to indicate this is a boot movl %edx, %esi # Pointer to boot_params table - movl %eax, 2f # Patch ljmpl instruction + + xorl %edx, %edx + movw %cs, %dx + shll $4, %edx # Patch ljmpl instruction + addl %edx, 2f jmp 1f # Short jump to flush instruction q. 1: movw $__BOOT_DS, %cx + xorl %ebx, %ebx # Per protocol + xorl %ebp, %ebp # Per protocol + xorl %edi, %edi # Per protocol movl %cr0, %edx orb $1, %dl # Protected mode (PE) bit movl %edx, %cr0 + + .byte 0x66, 0xea # ljmpl opcode +2: .long 3f # Offset + .word __BOOT_CS # Segment - movw %cx, %ds - movw %cx, %es - movw %cx, %fs - movw %cx, %gs - movw %cx, %ss + .code32 +3: + movl %ecx, %ds + movl %ecx, %es + movl %ecx, %fs + movl %ecx, %gs + movl %ecx, %ss # Jump to the 32-bit entrypoint - .byte 0x66, 0xea # ljmpl opcode -2: .long 0 # offset - .word __BOOT_CS # segment - + jmpl *%eax + .size protected_mode_jump, .-protected_mode_jump