// vim: ft=gas:et:sw=12:ts=12:sts=12

            .set        SS_CODE16,  0x08
            .set        SS_DATA16,  0x10
            .set        SS_CODE32,  0x18
            .set        SS_DATA32,  0x20



.macro      PROT16
            .code32
            mov         $SS_DATA16, %ax
            mov         %ax, %ds
            mov         %ax, %es
            mov         %ax, %ss
            ljmp        $SS_CODE16, $9f
9:          .code16
.endm

.macro      PROT32
            .code16
            mov         $SS_DATA32, %ax
            mov         %ax, %ds
            mov         %ax, %es
            mov         %ax, %ss
            ljmp        $SS_CODE32, $9f
9:          .code32
.endm

.macro      REAL
            mov         %cr0, %eax
            and         $0xFFFE, %ax
            mov         %eax, %cr0
            xor         %ax, %ax
            mov         %ax, %ds
            mov         %ax, %es
            mov         real_ss, %ax
            mov         %ax, %ss
            shl         $4, %eax
            sub         %eax, %esp
            ljmp        $0x0000, $9f
9:
.endm

.macro      PROT
            mov         %cr0, %eax
            or          $1, %eax
            mov         %eax, %cr0
            xor         %eax, %eax
            mov         $SS_DATA16, %ax
            mov         %ax, %ds
            mov         %ax, %es
            mov         %ax, %ss
            mov         real_ss, %ax
            shl         $4, %eax
            add         %eax, %esp
.endm