The Atari Compendium/The Atari Compendium (Toad Computers) (1994).iso/files/umich/tex/undump.zoo/undump.c

C/C++ Source or Header | 1989-09-21 | 5KB | 222 lines

/*
 *  undump new old <args>
 *    undump the memory image of old to new
 *    old is run with args, and when it exits, its memory image is
 *    undump'ed into new.
 *    Gcc probably required.
 *
 *        ++jrb    [e-mail]
 */
#include <stdio.h>
#include <basepage.h>
#include <st-out.h>
#include <osbind.h>
#include <string.h>

#define BSIZ    8192L
char buf[BSIZ];
char oldname[FILENAME_MAX], newname[FILENAME_MAX];

static unsigned long getlong(FILE *f)
{
    unsigned long l;
    if(fread(&l, sizeof l, 1, f) != 1)
    {
    fprintf(stderr,"%s: unexpected EOF\n", oldname);
    exit(92);
    }
    return l;
}

static void copy(FILE *, FILE *, unsigned long);
static void makeenv(int, char **, char **);

int main(int argc, char **argv, char **envp)
{
    FILE *new, *old;
    FILE *fopen();
    struct aexec newhead, oldhead;
    BASEPAGE *bp;
    long l;
    unsigned long roffset, ul;
    char *patchloc;
    unsigned long getlong(FILE *);

    /* chk args */
    if(argc < 3)
    {
    fprintf(stderr,"usage: undump new old [args..]\n");
    exit(1);
    }

    /* open files */
    if((new = fopen(argv[1], "wb")) == NULL)
    {
    perror(argv[1]);
    exit(2);
    }
    strncpy(newname, argv[1], FILENAME_MAX);
    if((old = fopen(argv[2], "rb")) == NULL)
    {
    perror(argv[2]);
    exit(3);
    }
    strncpy(oldname, argv[2], FILENAME_MAX);

    /* read header from old */
    if(fread(&oldhead, sizeof oldhead, 1, old) != 1)
    {
    perror(oldname);
    exit(4);
    }
    if(A_BADMAG(oldhead))    /* check its magic # */
    {
    fprintf(stderr,"%s: bad magic number 0x%x\n", oldname,oldhead.a_magic);
    exit(5);
    }
    /* make up new head */
    newhead = oldhead;
    newhead.a_data = oldhead.a_data + oldhead.a_bss;
    newhead.a_bss  = 0L;

    /* write new head */
    if(fwrite(&newhead, sizeof newhead, 1, new) != 1)
    {
    perror(newname);
    exit(6);
    }

    /* pick up args and make env */
    makeenv(argc, argv, envp);
    /* &buf[0] == command tail, &buf[130] == envp */

    /* load old into mem and grab basepage */
    if((l = Pexec(PE_LOAD, oldname, buf, &buf[130])) < 0)
    {
    fprintf(stderr,"%s: could'nt load\n", oldname);
    exit(7);
    }
    bp = (BASEPAGE *)l;
    roffset = (unsigned long)(bp->p_tbase);    /* grab reloc offset */
    bzero(bp->p_bbase, bp->p_blen);    /* not sure if this is needed */

    /* now do the just go */
    (void)Pexec(PE_GO, 0L, bp, 0L);

    /* un-relocate stuff in the text and data segments in core,
       and then dump it all into new */
    /* seek to reloc part of old */
    if(fseek(old, A_SYMOFF(oldhead) + oldhead.a_syms, SEEK_SET) < 0)
    {
    perror(oldname);
    exit(8);
    }

    /* step through relocs, reading relocs from old, and unrelocating */
    /* the corresponding items in core */
    ul = getlong(old); /* initial off from begining of text */
    patchloc = (char *)(roffset + ul);
    while(1)
    {
    *((unsigned long *)patchloc) -= roffset; /* un-reloc */
      more:
    if((ul = (unsigned long)getc(old)) == 0)
        break;    /* all done */
    if(ul == 1)
    {
        patchloc += 254L;
        goto more;
    }
    else if(ul == 3)
    {
        fprintf(stderr,"WARNING: illegal reloc %ld (ignored)\n", ul);
        goto more;
    } /* note we let ul==2 pass thru */
    patchloc += ul;
    }

    /* dump text+data+bss from core into new */
    if(fwrite(bp->p_tbase, newhead.a_text + newhead.a_data, 1, new) != 1)
    {
    perror(newname);
    exit(11);
    }
    if(fseek(old, A_SYMOFF(oldhead), SEEK_SET) < 0)
    {
    perror(oldname);
    exit(12);
    }

    /* copy rest of old into new (ie. the symt if any and the reloc) */
    copy(old, new, 0x7fffffffL);


    fclose(new);
    fclose(old);
    return 0;
}

/*
 * copy from -> to upto count bytes or EOF
 */
static void copy(FILE *from, FILE *to, unsigned long count)
{
    register unsigned long n;

    while(count > 0)
    {
    n = (count > BSIZ) ? BSIZ : count;
    if((n = fread(buf, 1, n, from)) <= 0)
        return;
    if(fwrite(buf, 1, n, to) != n)
    {
        perror(newname);
        exit(13);
    }
    count -= n;
    }
}

extern char **environ;

static void makeenv(int argc, char **argv, char **envp)
{
    int i, count, l;
    char *p;

    bzero(buf, 128L);
    if(envp == NULL)
    envp = environ;
    p = &buf[130];
    if(envp)
    {
    for(; *envp; envp++)
    {
        strcpy(p, *envp);
        p += (strlen(*envp) + 1);
    }
    }
    strcpy(p, "ARGV=");
    p += (strlen(p) + 1);
    strcpy(p, argv[2]);
    p += (strlen(p) + 1);
    strcpy(buf, " ");
    for(count = 0, i = 3; i < argc; i++)
    {
    l = strlen(argv[i]);
    if( (count += l) < 127)
    {
        strcat(buf, argv[i]);
        if((i+1) < argc)
        {
        strcat(buf, " ");
        count++;
        }
    }
    strcpy(p, argv[i]);
    p += (l+1);
    }
    *p++ = '\0'; *p = '\0';
    buf[0] = strlen(&buf[1]);
}