| /svarcom/command.c |
|---|
| 48,7 → 48,6 |
| #include <i86.h> |
| #include <dos.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <process.h> |
| 58,41 → 57,16 |
| struct config { |
| int locate; |
| int install; |
| int envsiz; |
| } cfg; |
| #define RMOD_OFFSET_ENVSEG 0x08 |
| #define RMOD_OFFSET_INPBUFF 0x0A |
| #define RMOD_OFFSET_ROUTINE 0x8C |
| /* returns segment where rmod is installed */ |
| unsigned short rmod_install(unsigned short envsize) { |
| char far *myptr, far *mcb; |
| unsigned short install_routine(void) { |
| char far *ptr, far *mcb; |
| unsigned short far *owner; |
| unsigned int rmodseg = 0xffff; |
| unsigned int envseg = 0; |
| unsigned int memseg = 0xffff; |
| /* read my current env segment from PSP */ |
| _asm { |
| push ax |
| push bx |
| mov bx, 0x2c |
| mov ax, [bx] |
| mov envseg, ax |
| pop bx |
| pop ax |
| } |
| printf("original (PSP) env buffer at %04X\r\n", envseg); |
| /* if custom envsize requested, convert it to number of paragraphs */ |
| if (envsize != 0) { |
| envsize += 15; |
| envsize /= 16; |
| } |
| _asm { |
| /* link in the UMB memory chain for enabling high-memory allocation (and save initial status on stack) */ |
| mov ax, 0x5802 /* GET UMB LINK STATE */ |
| int 0x21 |
| 110,21 → 84,12 |
| mov ax, 0x5801 |
| mov bx, 0x0082 |
| int 0x21 |
| /* ask for a memory block and save the given segment to rmodseg */ |
| /* ask for a memory block and save the given segment to memseg */ |
| mov ah, 0x48 |
| mov bx, (rmod_len + 15) / 16 |
| int 0x21 |
| jc ALLOC_FAIL |
| mov rmodseg, ax |
| /* ask for a memory block for the environment and save it to envseg (only if custom size requested) */ |
| mov bx, envsize |
| test bx, bx |
| jz ALLOC_FAIL |
| mov ah, 0x48 |
| int 0x21 |
| jc ALLOC_FAIL |
| mov envseg, ax |
| mov memseg, ax |
| ALLOC_FAIL: |
| /* restore initial allocation strategy */ |
| mov ax, 0x5801 |
| 136,35 → 101,15 |
| int 0x21 |
| } |
| if (rmodseg == 0xffff) { |
| if (memseg == 0xffff) { |
| puts("malloc error"); |
| return(0xffff); |
| } |
| /* copy rmod to its destination */ |
| myptr = MK_FP(rmodseg, 0); |
| _fmemcpy(myptr, rmod, rmod_len); |
| /* mark rmod memory as "self owned" */ |
| mcb = MK_FP(rmodseg - 1, 0); |
| ptr = MK_FP(memseg, 0); |
| mcb = MK_FP(memseg - 1, 0); |
| owner = (void far *)(mcb + 1); |
| *owner = rmodseg; |
| _fmemcpy(mcb + 8, "SVARCOM", 8); |
| _fmemcpy(ptr, rmod, rmod_len); |
| /* mark env memory as "self owned" (only if allocated by me) */ |
| if (envsize != 0) { |
| printf("envseg allocated at %04X:0000 with %u paragraphs\r\n", envseg, envsize); |
| mcb = MK_FP(envseg - 1, 0); |
| owner = (void far *)(mcb + 1); |
| *owner = rmodseg; |
| _fmemcpy(mcb + 8, "SVARENV", 8); |
| } |
| /* write env segment to rmod buffer */ |
| owner = MK_FP(rmodseg, RMOD_OFFSET_ENVSEG); |
| *owner = envseg; |
| /* |
| printf("MCB sig: %c\r\nMCB owner: 0x%04X\r\n", mcb[0], *owner); |
| { |
| int i; |
| 180,41 → 125,28 |
| } |
| } |
| printf("\r\n"); |
| }*/ |
| } |
| return(rmodseg); |
| /* mark memory as "self owned" */ |
| *owner = memseg; |
| _fmemcpy(mcb + 8, "COMMAND", 8); |
| return(memseg); |
| } |
| /* returns zero if s1 starts with s2 */ |
| static int strstartswith(const char *s1, const char *s2) { |
| while (*s2 != 0) { |
| if (*s1 != *s2) return(-1); |
| s1++; |
| s2++; |
| } |
| return(0); |
| } |
| static void parse_argv(struct config *cfg, int argc, char **argv) { |
| int i; |
| memset(cfg, 0, sizeof(*cfg)); |
| for (i = 1; i < argc; i++) { |
| if (strcmp(argv[i], "/locate") == 0) { |
| cfg->locate = 1; |
| } |
| if (strstartswith(argv[i], "/e:") == 0) { |
| cfg->envsiz = atoi(argv[i]+3); |
| if (cfg->envsiz < 64) cfg->envsiz = 0; |
| } |
| } |
| } |
| /* scan memory for my shared buffer, return segment of buffer */ |
| static unsigned short rmod_find(void) { |
| static unsigned short find_shm(void) { |
| unsigned short i; |
| unsigned short far *pattern; |
| 221,10 → 153,10 |
| /* iterate over all paragraphs, looking for my signature */ |
| for (i = 0; i != 65535; i++) { |
| pattern = MK_FP(i, 0); |
| if (pattern[0] != 0x1983) continue; |
| if (pattern[1] != 0x1985) continue; |
| if (pattern[2] != 0x2017) continue; |
| if (pattern[3] != 0x2019) continue; |
| if (pattern[1] != 0x1983) continue; |
| if (pattern[2] != 0x1985) continue; |
| if (pattern[3] != 0x2017) continue; |
| if (pattern[4] != 0x2019) continue; |
| return(i); |
| } |
| return(0xffff); |
| 274,16 → 206,16 |
| int main(int argc, char **argv) { |
| struct config cfg; |
| unsigned short rmod_seg; |
| unsigned short far *rmod_envseg; |
| unsigned short env_seg = 0, rmod_seg, rmod_buff = 0; |
| void far *rmod_func; |
| parse_argv(&cfg, argc, argv); |
| rmod_seg = rmod_find(); |
| rmod_seg = find_shm(); |
| if (rmod_seg == 0xffff) { |
| rmod_seg = rmod_install(cfg.envsiz); |
| rmod_seg = install_routine(); |
| if (rmod_seg == 0xffff) { |
| puts("ERROR: rmod_install() failed"); |
| puts("ERROR: install_rmod() failed"); |
| return(1); |
| } else { |
| printf("rmod installed at seg 0x%04X\r\n", rmod_seg); |
| 292,16 → 224,15 |
| printf("rmod found at seg 0x%04x\r\n", rmod_seg); |
| } |
| rmod_envseg = MK_FP(rmod_seg, RMOD_OFFSET_ENVSEG); |
| { |
| unsigned short envsiz; |
| unsigned short far *sizptr = MK_FP(*rmod_envseg - 1, 3); |
| envsiz = *sizptr; |
| envsiz *= 16; |
| printf("rmod_inpbuff at %04X:%04X, env_seg at %04X:0000 (env_size = %u bytes)\r\n", rmod_seg, RMOD_OFFSET_INPBUFF, *rmod_envseg, envsiz); |
| rmod_func = MK_FP(rmod_seg, 0x0A); |
| /* fetch offset of buffer (result in AX) */ |
| _asm { |
| call dword ptr [rmod_func] |
| mov rmod_buff, ax |
| } |
| printf("rmod_buff at %04X:%04X\r\n", rmod_seg, rmod_buff); |
| _asm { |
| /* set the int22 handler in my PSP to rmod so DOS jumps to rmod after I terminate */ |
| mov bx, 0x0a |
| 309,11 → 240,17 |
| mov [bx], ax |
| mov ax, rmod_seg |
| mov [bx+2], ax |
| /* get the segment of my environment */ |
| mov bx, 0x2c |
| mov ax, [bx] |
| mov env_seg, ax |
| } |
| printf("env_seg at %04X\r\n", env_seg); |
| for (;;) { |
| int i, argcount; |
| char far *cmdline = MK_FP(rmod_seg, RMOD_OFFSET_INPBUFF + 2); |
| char far *cmdline = MK_FP(rmod_seg, rmod_buff + 2); |
| char path[256] = "C:\\>$"; |
| char const *argvlist[256]; |
| union REGS r; |
| 336,7 → 273,7 |
| mov ax, rmod_seg |
| push ax |
| pop ds |
| mov dx, RMOD_OFFSET_INPBUFF |
| mov dx, rmod_buff |
| /* execute either DOS input or DOSKEY */ |
| test bl, bl /* zf set if no DOSKEY present */ |
| 373,7 → 310,7 |
| /* TODO is it an internal command? */ |
| if (strcmp(argvlist[0], "set") == 0) { |
| cmd_set(argcount, argvlist, *rmod_envseg); |
| cmd_set(argcount, argvlist, env_seg); |
| continue; |
| } |
| /svarcom/rmod.asm |
|---|
| 13,23 → 13,23 |
| section .text ; all goes into code segment |
| ; offset |
| SIG1 dw 0x1983 ; +0 |
| SIG2 dw 0x1985 ; +2 |
| SIG3 dw 0x2017 ; +4 |
| SIG4 dw 0x2019 ; +6 |
| jmp short skipsig |
| ; environment segment - this is updated by SvarCOM at init time |
| ENVSEG dw 0 ; +8 |
| SIG1 dw 0x1983 |
| SIG2 dw 0x1985 |
| SIG3 dw 0x2017 |
| SIG4 dw 0x2019 |
| ; input buffer used for the "previous command" history |
| BUF000 db 128, 0 ; +0Ah |
| BUF064 db "0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF" |
| BUF128 db "0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF" |
| ; service routine: used by the transient part of svarcom, returns: |
| ; AX = offset of input buffer history block |
| ; BX = offset where environment's segment is stored (patched at install time) |
| inputroutine: |
| mov ax, BUF000 |
| mov bx, ENVSEG |
| retf |
| skipsig: |
| skipsig: ; +8Ch |
| ; set up CS=DS=SS and point SP to my private stack buffer |
| mov ax, cs |
| mov ds, ax |
| 38,8 → 38,7 |
| mov sp, STACKPTR |
| ; prepare the exec param block |
| mov ax, [ENVSEG] |
| mov [EXEC_PARAM_REC], ax |
| ;mov [EXEC_PARAM_REC], word 0 |
| mov ax, COMSPEC |
| mov [EXEC_PARAM_REC+2], ax |
| mov [EXEC_PARAM_REC+4], ds |
| 84,7 → 83,15 |
| COMSPEC db "C:\SVN\SVARDOS\SVARCOM\COMMAND.COM" |
| COMSPCZ db 0 |
| ; input buffer used for the "previous command" history |
| BUF000 db 128, 0 |
| BUF064 db "0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF" |
| BUF128 db "0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF" |
| ; FreeDOS int 21h functions that I use require at least 32 bytes of stack, |
| ; here I allocate 64 bytes to be sure |
| STACKBUF db "0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF" |
| STACKPTR db "xx" |
| ; environment segment - this is updated by SvarCOM at init time |
| ENVSEG dw 0 |
| /svarcom/rmod.h |
|---|
| 1,25 → 1,25 |
| const char rmod[] = { |
| 131, 25,133, 25, 23, 32, 25, 32, 0, 0,128, 0, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, |
| 52, 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70,140,200,142,216, |
| 142,192,142,208,188,106, 1,161, 8, 0,163,208, 0,184, 7, 1, |
| 163,210, 0,140, 30,212, 0,184, 0, 75,186, 7, 1,187,208, 0, |
| 205, 33,115,216, 4, 48,162,226, 0,180, 9,186,222, 0,198, 6, |
| 41, 1, 36,205, 33,198, 6, 41, 1, 0,180, 8,205, 33,235,188, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 69, 82, |
| 82, 32,120, 44, 32, 70, 65, 73, 76, 69, 68, 32, 84, 79, 32, 76, |
| 79, 65, 68, 32, 67, 79, 77, 77, 65, 78, 68, 46, 67, 79, 77, 32, |
| 70, 82, 79, 77, 58, 13, 10, 67, 58, 92, 83, 86, 78, 92, 83, 86, |
| 65, 82, 68, 79, 83, 92, 83, 86, 65, 82, 67, 79, 77, 92, 67, 79, |
| 77, 77, 65, 78, 68, 46, 67, 79, 77, 0, 48, 49, 50, 51, 52, 53, |
| 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, 53, |
| 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, 53, |
| 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, 53, |
| 54, 55, 56, 57, 65, 66, 67, 68, 69, 70,120,120}; |
| #define rmod_len 364 |
| 235, 15,131, 25,133, 25, 23, 32, 25, 32,184,169, 0,187,109, 1, |
| 203,140,200,142,216,142,192,142,208,188,107, 1,184,134, 0,163, |
| 81, 0,140, 30, 83, 0,184, 0, 75,186,134, 0,187, 79, 0,205, |
| 33,115,222, 4, 48,162, 97, 0,180, 9,186, 93, 0,198, 6,168, |
| 0, 36,205, 33,198, 6,168, 0, 0,180, 8,205, 33,235,194, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 69, 82, 82, |
| 32,120, 44, 32, 70, 65, 73, 76, 69, 68, 32, 84, 79, 32, 76, 79, |
| 65, 68, 32, 67, 79, 77, 77, 65, 78, 68, 46, 67, 79, 77, 32, 70, |
| 82, 79, 77, 58, 13, 10, 67, 58, 92, 83, 86, 78, 92, 83, 86, 65, |
| 82, 68, 79, 83, 92, 83, 86, 65, 82, 67, 79, 77, 92, 67, 79, 77, |
| 77, 65, 78, 68, 46, 67, 79, 77, 0,128, 0, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70, 48, 49, 50, 51, 52, |
| 53, 54, 55, 56, 57, 65, 66, 67, 68, 69, 70,120,120, 0, 0}; |
| #define rmod_len 367 |