/* arch/i386/gdt.c */
.set SEG_r0code, 1
.set SEG_r3code, 3
.set SEG_r3data, 4

.set IA32_SYSENTER_CS, 0x174

.section .text
.global sysexit
.type sysexit, @function
sysexit:
	mov 4(%esp), %edx
	mov 8(%esp), %ecx

	mov $(SEG_r3data << 3 | 3), %ax
	mov %ax, %ds
	mov %ax, %es
	mov %ax, %fs
	mov %ax, %gs

	// enable paging
	mov %cr0, %eax
	or $0x80000000, %eax
	mov %eax, %cr0

	sysexit


.global sysenter_setup
.type sysenter_setup, @function
sysenter_setup:
	xor %edx, %edx
	mov $(SEG_r0code << 3), %eax
	mov $IA32_SYSENTER_CS, %ecx
	wrmsr
	ret