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/* DOSMEM.S */
/*
** Copyright (C) 1993 C.W. Sandmann
**
** This file may be freely distributed as long as the author's name remains.
** Extender environment independent way to set up Real area 1Mb access.
** Procedure takes a single argument %eax which contains the real area offset.
** After call, access may be made with "%gs:(%eax)"
*/
.text
.align 2
.globl dosmemsetup
dosmemsetup: /* no params, expected ASM call only */
pushl %eax
movzwl __core_select,%eax
testl %eax,%eax
je old_go32 /* Image run with pre-DPMI extender */
movw %ax,%gs /* Use real area selector */
popl %eax /* Plus real offset */
andl $0x0fffffff,%eax /* Clear any linear access bits */
ret
.align 2,0x90
old_go32:
push %ds
pop %gs /* Use arena selector */
popl %eax
orl $0xe0000000,%eax /* Plus linear access area */
ret
.align 2
.globl _dosmemget
_dosmemget: /* long offset, long len, long *buf */
push %gs
movl 8(%esp),%eax /* offset */
call dosmemsetup
movl 12(%esp),%ecx /* length */
movl 16(%esp),%edx /* arena offset */
pushl %esi
pushl %edi
movl %eax,%esi
movl %edx,%edi
push %ds
push %es
push %ds
pop %es
push %gs
pop %ds
cld
rep
movsb /* move ECX bytes from Real area */
pop %es
pop %ds
popl %edi
popl %esi
pop %gs
ret
.align 2
.globl _dosmemput
_dosmemput: /* long *buf, long len, long offset */
push %gs
movl 16(%esp),%eax /* offset */
call dosmemsetup
movl 12(%esp),%ecx /* length */
movl 8(%esp),%edx /* arena offset */
pushl %esi
pushl %edi
movl %eax,%edi
movl %edx,%esi
push %es
push %gs
pop %es
cld
rep
movsb /* move ECX bytes to Real area */
pop %es
popl %edi
popl %esi
pop %gs
ret
.align 2 /* 8(bp) 12(bp) 16(bp) 20(bp) 24(bp) */
.globl _movedata /* src_sel, src_ofs, dest_sel, dest_ofs, len */
_movedata:
pushl %ebp
movl %esp,%ebp
pushw %ds
pushw %es
pushl %esi
pushl %edi
movl 8(%ebp),%eax
movw %ax,%ds
movl 12(%ebp),%esi
movl 16(%ebp),%eax
movw %ax,%es
movl 20(%ebp),%edi
movl 24(%ebp),%ecx
pushl %ecx
shrl $2,%ecx
jcxz no_big_move
rep
movsl
no_big_move:
popl %ecx
andl $3,%ecx
jcxz no_little_move
rep
movsb
no_little_move:
popl %edi
popl %esi
popw %es
popw %ds
leave
ret
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