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/*
** xms.c -- C bindings for xms API - implemented
** Author: Kent Williams william@umaxc.weeg.uiowa.edu
*/
#pragma inline
#include <stdio.h>
#include <stdlib.h>
#include "xms.h"
static void far xms_spoof(void);
static void (far *xms_entry)(void) = xms_spoof;
char xms_error;
int
xms_installed(void) {
asm mov ax,0x4300 /* get installation status */
asm int 0x2f /* call driver */
asm mov ah,1 /* return true if present */
asm cmp al,0x80 /* are you there? */
asm je __present
asm xor ax,ax /* no, return false */
__present:
asm xchg ah,al /* if present, set ax to 1 */
asm cbw
return _AX;
}
static void
xms_get_entry(void) {
asm mov ax,0x4310 /* get driver entry */
asm int 0x2f /* call multiplex */
asm mov word ptr xms_entry,bx
asm mov word ptr (xms_entry+2),es
}
static void far
xms_spoof(void) {
asm push ax
asm push bx
asm push cx
asm push dx
asm push si
asm push di
asm push es
asm push ds
if(!xms_installed()) {
fputs("No XMS driver installed\n",stderr);
exit(1);
} else
xms_get_entry();
asm pop ds
asm pop es
asm pop di
asm pop si
asm pop dx
asm pop cx
asm pop bx
asm pop ax
xms_entry();
}
xms_version_info *
xms_get_version_info(void) {
unsigned xms_ver,xmm_ver,hma_indicator;
static xms_version_info x;
asm xor ah,ah
asm call [xms_entry]
asm mov xms_error,bl
asm mov xms_ver,ax
asm mov xmm_ver,bx
asm mov hma_indicator,dx
xms_ver = (xms_ver & 0xf) + (((xms_ver >> 4) & 0xf) * 10) +
((xms_ver >> 8) & 0xf) * 100 + ((xms_ver >> 12) & 0xf) * 1000;
xmm_ver = (xmm_ver & 0xf) + (((xmm_ver >> 4) & 0xf) * 10) +
((xmm_ver >> 8) & 0xf) * 100 + ((xmm_ver >> 12) & 0xf) * 1000;
x.xms_ver = xms_ver; x.xmm_ver = xmm_ver; x.hma_present = hma_indicator;
return &x;
}
xms_extended_info *
xms_query_extended_memory(void) {
unsigned max_free_block,total_extended_memory;
static xms_extended_info x;
asm mov ah,0x8
asm call [xms_entry]
asm mov xms_error,bl
asm mov max_free_block,ax
asm mov total_extended_memory,dx
x.max_free_block = max_free_block;
x.total_extended_memory = total_extended_memory;
return &x;
}
int
xms_hma_allocate(unsigned siz) {
asm mov ah,0x01
asm mov dx,word ptr siz
asm call [xms_entry]
asm mov xms_error,bl
/* xms returns 1 on success, 0 on failure. We need to invert this
** for the C idiom.
** if ax = 1 then not ax = 0xfffe and add ax,2 = 0
** if ax = 0 then not ax = 0xffff and add ax,2 = 1
*/
asm not ax
asm inc ax
asm inc ax
return _AX;
}
int
xms_hma_free(void) {
asm mov ah,0x02
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
int
xms_global_enable_a20(void) {
asm mov ah,0x03
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
int
xms_global_disable_a20(void) {
asm mov ah,0x4
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
int
xms_local_enable_a20(void) {
asm mov ah,0x5
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
int
xms_local_disable_a20(void) {
asm mov ah,0x6
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
int
xms_a20_status(void) {
asm mov ah,0x7
asm call [xms_entry]
asm mov xms_error,bl
return _AX;
}
int
xms_emb_allocate(emb_size_K_t siz) {
asm mov ah,0x9
asm mov dx,siz
asm call [xms_entry]
asm mov xms_error,bl
asm or ax,ax /* allocation succeed? */
asm jz alloc_failed /* no, return 0 */
asm xchg ax,dx /* yes, return handle */
asm jmp done
alloc_failed:
asm mov ax,-1
done:;
return _AX;
}
int
xms_emb_free(emb_handle_t handle) {
asm mov ah,0x0a
asm mov dx,handle
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
emb_handle_info *
xms_get_emb_handle_info(emb_handle_t handle) {
static emb_handle_info info;
unsigned char locks,handles;
emb_size_K_t siz;
asm mov ah,0x0e
asm mov dx,handle
asm call [xms_entry]
asm or ax,ax /* did call fail? */
asm jz call_failed
asm mov locks,bh
asm mov handles,bl
asm mov siz,dx
asm jmp short done
call_failed:
asm mov xms_error,bl
asm mov ax,1
asm mov word ptr siz,-1
done:
info.lock_count = locks;
info.handles_available = handles;
info.block_size = siz;
return siz == 0xffff ? NULL : &info;
}
int
xms_emb_resize(emb_handle_t handle,emb_size_K_t siz) {
asm mov ah,0xf
asm mov bx,siz
asm mov dx,handle
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
int
xms_move_emb(xms_move_param *x) {
xms_move_param far *x2 = (xms_move_param far *)x;
asm push ds
asm mov ah,0xb
asm lds si,x2
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
emb_off_t
xms_lock_emb(emb_handle_t handle) {
asm mov ah,0x0c
asm mov dx,handle
asm call [xms_entry]
asm cmp ax,0
asm je lock_failed
asm mov ax,bx /* return value in dx:ax */
asm mov xms_error,0
asm jmp lock_done
lock_failed:
asm mov dx,ax
asm mov xms_error,bl
lock_done:
;
asm pop bp /* these do the actual returning, */
asm ret /* the return below is to satisfy tcc */
return 0; /* we can't tell tcc that we filled DX:AX for
return, so we fake it to silence the warning */
}
int
xms_unlock_emb(emb_handle_t handle) {
asm mov ah,0x0d
asm mov dx,handle
asm call [xms_entry]
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
umb_info *
xms_umb_allocate(umb_size_t siz) {
static umb_info x;
unsigned segment,block_size;
asm mov ah,0x10
asm mov dx,siz
asm call [xms_entry]
asm mov xms_error,bl
asm mov segment,bx
asm mov block_size,dx
asm or ax,ax
asm jnz done
asm mov segment,ax
done:
x.segment = segment;
x.block_size = block_size;
return segment != 0 ? &x : NULL;
}
int
xms_umb_free(umb_segment_t segment) {
asm mov ah,0x11
asm mov dx,segment
asm call [xms_entry];
asm mov xms_error,bl
asm not ax
asm inc ax
asm inc ax
return _AX;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.