.code16
.globl vm86_code_start
.globl vm86_code_end
#define GET_OFFSET(x) ((x) - vm86_code_start + 0x100)
vm86_code_start:
movw $GET_OFFSET(hello_world), %dx
movb $0x09, %ah
int $0x21
/* prepare int 0x90 vector */
xorw %ax, %ax
movw %ax, %es
es movw $GET_OFFSET(int90_test), 0x90 * 4
es movw %cs, 0x90 * 4 + 2
/* launch int 0x90 */
int $0x90
/* test IF support */
movw $GET_OFFSET(IF_msg), %dx
movb $0x09, %ah
int $0x21
pushf
popw %dx
movb $0xff, %ah
int $0x21
cli
pushf
popw %dx
movb $0xff, %ah
int $0x21
sti
pushfl
popl %edx
movb $0xff, %ah
int $0x21
#if 0
movw $GET_OFFSET(IF_msg1), %dx
movb $0x09, %ah
int $0x21
pushf
movw %sp, %bx
andw $~0x200, (%bx)
popf
#else
cli
#endif
pushf
popw %dx
movb $0xff, %ah
int $0x21
pushfl
movw %sp, %bx
orw $0x200, (%bx)
popfl
pushfl
popl %edx
movb $0xff, %ah
int $0x21
movb $0x00, %ah
int $0x21
int90_test:
pushf
pop %dx
movb $0xff, %ah
int $0x21
movw %sp, %bx
movw 4(%bx), %dx
movb $0xff, %ah
int $0x21
movw $GET_OFFSET(int90_msg), %dx
movb $0x09, %ah
int $0x21
iret
int90_msg:
.string "INT90 started\n$"
hello_world:
.string "Hello VM86 world\n$"
IF_msg:
.string "VM86 IF test\n$"
IF_msg1:
.string "If you see a diff here, your Linux kernel is buggy, please update to 2.4.20 kernel\n$"
vm86_code_end: