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|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; MACRO definitions for expanded memory manager
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; 1. MACRO to save mapping context in case somebody else has
; mapped the page registers.
;
save_mapping_context macro
local save_agn_m,save_err_m,save_ok_m,save_exit_m
;
; the save mapping call for the above board -->
;
; mov ah,47h
; mov dx,handle
; int 67h
;
; on return ax = 0 signifies success
;
;
push ax ; save registers
push dx
;
; set up emm registers and execute call to save mapping context
;
save_agn_m:
mov dx,cs:[above_pid] ; get emm handle
mov ah,above_save_map_pid ; save map call
int 67h ; call the manager
or ah,ah ; is there an error?
jz save_ok_m ; if not we are done
;
; error in saving mapping context, check for error
;
cmp ah,above_error_busy ; if the emm manager was busy
jz save_agn_m ; we would like to try again
;
; unrecoverable error, indicate error type in al
;
pop dx
pop dx ; pop the regs off the stack
;
mov al,0aah ; drive not ready
cmp ah,above_error_cntxt_no_stack ;
jz save_err_m
cmp ah,above_error_second_save ;
ja save_err_m
mov al,0bbh ; general failure
save_err_m:
stc
jmp short save_exit_m
save_ok_m:
clc
pop dx
pop ax ; restore registers
save_exit_m:
endm
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; 2. MACRO to restore the mapping context saved earlier
;
restore_mapping_context macro
local rest_agn_m, rest_ok_m, rest_exit_m
;
; the restore above map call -->
;
; mov ah,48h
; mov dx,handle
; int 67h
; ah = 0 is success
;
;
push ax
pushf
;
rest_agn_m:
mov dx,cs:[above_pid] ; get emm handle
mov ah,above_restore_map_pid ; restore map call
int 67h ; call manager
or ah,ah ; is there any error
jz rest_ok_m ; if not go to finish up
;
; error condition, check for recoverable error
;
cmp ah,above_error_busy ; if manager was busy
jz rest_agn_m ; we sure can try again
cmp ah,above_error_no_cntxt ;
jz rest_ok_m ; ignore invalid pid error
;
; unrecoverable error
;
pop dx
pop dx
mov al,0bbh ; general failure
stc
jmp short rest_exit_m
;
rest_ok_m:
popf
pop ax
rest_exit_m:
;
endm
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; 3. MACRO to map a page in the physical page map onto a logical
; page.
;
; the map above page requires
; mov ah,44h
; mov dx,handle
; mov al,physical_page# (0-3)
; mov bx,logical_page#
; int 67H
; ah = 0 success and this routine zaps ax,dx and bx
;
map_page macro
local map_agn_m,map_exit_m,map_fin_m
;
mov ah,above_map ; function map page
mov dx,cs:[above_pid] ; get emm handle
;
push ax
;
map_agn_m:
pop ax
push ax
push bx
push dx ; "damn call above_map zaps these registers"
;
int 67h ; map call
pop dx
pop bx
;
or ah,ah ; is there an error?
jz map_fin_m ; if not go to finish up
;
; error condition - check for recoverable error
;
cmp ah,above_error_busy ; if manager was busy
jz map_agn_m ; we sure can try again
;
; unrecoverable error
;
pop ax
mov al,0aah ; device not ready error
stc
jmp short map_exit_m
;
; exit point
;
map_fin_m:
clc
pop ax
map_exit_m:
;
endm
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; OTHER MACROS
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; 1) MACRO to switch es:di with ds:si
;
src_dest_switch macro
;
push ds
push es
push si
mov si,di
pop di
pop ds
pop es
;
endm
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
