149 lines
2.5 KiB
ArmAsm
149 lines
2.5 KiB
ArmAsm
|
/* $NetBSD: comio.S,v 1.4 2003/04/16 14:23:11 dsl Exp $ */
|
||
|
|
|
||
|
|
/* serial console handling
|
||
|
|
modelled after code in FreeBSD:sys/i386/boot/netboot/start2.S
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <machine/asm.h>
|
||
|
|
|
||
|
|
.text
|
||
|
|
|
||
|
|
/**************************************************************************
|
||
|
|
INIT - Initialization (com number)
|
||
|
|
**************************************************************************/
|
||
|
|
ENTRY(cominit)
|
||
|
|
push %ebp
|
||
|
|
mov %esp,%ebp
|
||
|
|
push %ebx
|
||
|
|
push %edx
|
||
|
|
push %esi
|
||
|
|
push %edi
|
||
|
|
|
||
|
|
movl 8(%ebp), %edx
|
||
|
|
|
||
|
|
call _C_LABEL(prot_to_real) # enter real mode
|
||
|
|
.code16
|
||
|
|
|
||
|
|
# Initialize the serial port (dl) to 9600 baud, 8N1.
|
||
|
|
movb $0xe3, %al
|
||
|
|
movb $0, %ah
|
||
|
|
int $0x14
|
||
|
|
mov %ax,%bx
|
||
|
|
|
||
|
|
calll _C_LABEL(real_to_prot) # back to protected mode
|
||
|
|
.code32
|
||
|
|
|
||
|
|
xor %eax,%eax
|
||
|
|
mov %bx,%ax
|
||
|
|
|
||
|
|
pop %edi
|
||
|
|
pop %esi
|
||
|
|
pop %edx
|
||
|
|
pop %ebx
|
||
|
|
pop %ebp
|
||
|
|
ret
|
||
|
|
|
||
|
|
/**************************************************************************
|
||
|
|
PUTC - Print a character (char, com number)
|
||
|
|
**************************************************************************/
|
||
|
|
ENTRY(computc)
|
||
|
|
push %ebp
|
||
|
|
mov %esp,%ebp
|
||
|
|
push %ecx
|
||
|
|
push %ebx
|
||
|
|
push %edx
|
||
|
|
push %esi
|
||
|
|
push %edi
|
||
|
|
|
||
|
|
movb 8(%ebp),%cl
|
||
|
|
movl 12(%ebp),%edx
|
||
|
|
|
||
|
|
call _C_LABEL(prot_to_real) # enter real mode
|
||
|
|
.code16
|
||
|
|
|
||
|
|
movb %cl,%al
|
||
|
|
movb $0x01, %ah
|
||
|
|
int $0x14
|
||
|
|
|
||
|
|
movb %ah,%bl
|
||
|
|
|
||
|
|
calll _C_LABEL(real_to_prot) # back to protected mode
|
||
|
|
.code32
|
||
|
|
|
||
|
|
xor %eax,%eax
|
||
|
|
movb %bl,%al
|
||
|
|
|
||
|
|
pop %edi
|
||
|
|
pop %esi
|
||
|
|
pop %edx
|
||
|
|
pop %ebx
|
||
|
|
pop %ecx
|
||
|
|
pop %ebp
|
||
|
|
ret
|
||
|
|
|
||
|
|
/**************************************************************************
|
||
|
|
GETC - Get a character (com number)
|
||
|
|
**************************************************************************/
|
||
|
|
ENTRY(comgetc)
|
||
|
|
push %ebp
|
||
|
|
mov %esp,%ebp
|
||
|
|
push %ebx
|
||
|
|
push %edx
|
||
|
|
push %esi
|
||
|
|
push %edi
|
||
|
|
|
||
|
|
movl 8(%ebp),%edx
|
||
|
|
|
||
|
|
call _C_LABEL(prot_to_real) # enter real mode
|
||
|
|
.code16
|
||
|
|
|
||
|
|
movb $0x02, %ah
|
||
|
|
int $0x14
|
||
|
|
mov %ax, %bx
|
||
|
|
|
||
|
|
calll _C_LABEL(real_to_prot) # back to protected mode
|
||
|
|
.code32
|
||
|
|
|
||
|
|
xor %eax,%eax
|
||
|
|
mov %bx,%ax
|
||
|
|
|
||
|
|
pop %edi
|
||
|
|
pop %esi
|
||
|
|
pop %edx
|
||
|
|
pop %ebx
|
||
|
|
pop %ebp
|
||
|
|
ret
|
||
|
|
|
||
|
|
/**************************************************************************
|
||
|
|
ISKEY - Check for keyboard interrupt (com number)
|
||
|
|
**************************************************************************/
|
||
|
|
ENTRY(comstatus)
|
||
|
|
push %ebp
|
||
|
|
mov %esp,%ebp
|
||
|
|
push %ebx
|
||
|
|
push %edx
|
||
|
|
push %esi
|
||
|
|
push %edi
|
||
|
|
|
||
|
|
movl 8(%ebp),%edx
|
||
|
|
|
||
|
|
call _C_LABEL(prot_to_real) # enter real mode
|
||
|
|
.code16
|
||
|
|
|
||
|
|
movb $0x03, %ah
|
||
|
|
int $0x14
|
||
|
|
mov %ax,%bx
|
||
|
|
|
||
|
|
calll _C_LABEL(real_to_prot) # back to protected mode
|
||
|
|
.code32
|
||
|
|
|
||
|
|
xor %eax,%eax
|
||
|
|
mov %bx,%ax
|
||
|
|
|
||
|
|
pop %edi
|
||
|
|
pop %esi
|
||
|
|
pop %edx
|
||
|
|
pop %ebx
|
||
|
|
pop %ebp
|
||
|
|
ret
|