Subversion Repositories SvarDOS

Rev

Rev 463 | Rev 490 | Go to most recent revision | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 463 Rev 465
Line 67... Line 67...
67 
; exec an application preset (by SvarCOM) in the ExecParamRec
 67 
; exec an application preset (by SvarCOM) in the ExecParamRec
68 
mov ax, 0x4B00         ; DOS 2+ - load & execute program
 68 
mov ax, 0x4B00         ; DOS 2+ - load & execute program
69 
mov dx, EXECPROG       ; DS:DX  - ASCIZ program name (preset at PSP[already)
 69 
mov dx, EXECPROG       ; DS:DX  - ASCIZ program name (preset at PSP[already)
70 
mov bx, EXEC_PARAM_REC ; ES:BX  - parameter block pointer
 70 
mov bx, EXEC_PARAM_REC ; ES:BX  - parameter block pointer
71 
int 0x21
 71 
int 0x21
72 
mov [EXECPROG], byte 0 ; make sure to spawn command.com after app exits
 72 
mov [cs:EXECPROG], byte 0 ; do not run app again (+DS might have been changed)
73 
 
 73 
 
74 
jmp short skipsig      ; enforce valid ds/ss/etc (can be lost after int 21,4b)
 74 
jmp short skipsig      ; enforce valid ds/ss/etc (can be lost after int 21,4b)
75 
 
 75 
 
76 
EXEC_COMMAND_COM:
 76 
EXEC_COMMAND_COM:
77 
 
 77 
 
Line 100... Line 100...
100 
USEDEFAULTCOMSPEC:
 100 
USEDEFAULTCOMSPEC:
101 
 
 101 
 
102 
; prepare the exec param block
 102 
; prepare the exec param block
103 
mov ax, [PSP_ENVSEG]
 103 
mov ax, [PSP_ENVSEG]
104 
mov [EXEC_PARAM_REC], ax
 104 
mov [EXEC_PARAM_REC], ax
105 
mov ax, CMDTAIL
 - 
 
106 
mov [EXEC_PARAM_REC+2], ax
 105 
mov [EXEC_PARAM_REC+2], word CMDTAIL
107 
mov [EXEC_PARAM_REC+4], cs
 106 
mov [EXEC_PARAM_REC+4], cs
108 
 
 107 
 
109 
; execute command.com
 108 
; execute command.com
110 
mov ax, 0x4B00         ; DOS 2+ - load & execute program
 109 
mov ax, 0x4B00         ; DOS 2+ - load & execute program
111 
push es                ;
 110 
push es                ;
Line 138... Line 137...
138 
 
 137 
 
139 
; back to program start
 138 
; back to program start
140 
jmp skipsig
 139 
jmp skipsig
141 
 
 140 
 
142 
; command.com tail arguments, in PSP format: length byte followed by args and
 141 
; command.com tail arguments, in PSP format: length byte followed by args and
143 
; terminated with \r)
 142 
; terminated with \r) - a single 0x0A byte is passed so SvarCOM knows it is
- 
 
 143 
; called as respawn (as opposed to being invoked as a normal application)
- 
 
 144 
; this allows multiple copies of SvarCOM to stack upon each other.
144 
CMDTAIL db 0x00, 0x0D
 145 
CMDTAIL db 0x01, 0x0A, 0x0D
145 
 
 146 
 
146 
ERRLOAD db "ERR x, FAILED TO LOAD COMMAND.COM", 13, 10, '$'
 147 
ERRLOAD db "ERR x, FAILED TO LOAD COMMAND.COM", 13, 10, '$'
147 
 
 148 
 
148 
; DOS int 21h functions that I use require at least 32 bytes of stack, here I
 149 
; DOS int 21h functions that I use require at least 32 bytes of stack, here I
149 
; allocate 64 bytes to be sure
 150 
; allocate 64 bytes to be sure