Annotation of linux/tools/build.c, revision 1.1.1.6

1.1.1.2   root        1: /*
                      2:  *  linux/tools/build.c
                      3:  *
                      4:  *  (C) 1991  Linus Torvalds
                      5:  */
                      6: 
                      7: /*
                      8:  * This file builds a disk-image from three different files:
                      9:  *
                     10:  * - bootsect: max 510 bytes of 8086 machine code, loads the rest
                     11:  * - setup: max 4 sectors of 8086 machine code, sets up system parm
                     12:  * - system: 80386 code for actual system
                     13:  *
                     14:  * It does some checking that all files are of the correct type, and
                     15:  * just writes the result to stdout, removing headers and padding to
                     16:  * the right amount. It also writes some system data to stderr.
                     17:  */
                     18: 
1.1.1.3   root       19: /*
                     20:  * Changes by tytso to allow root device specification
                     21:  */
                     22: 
1.1       root       23: #include <stdio.h>     /* fprintf */
1.1.1.2   root       24: #include <string.h>
1.1       root       25: #include <stdlib.h>    /* contains exit */
                     26: #include <sys/types.h> /* unistd.h needs this */
1.1.1.2   root       27: #include <sys/stat.h>
                     28: #include <linux/fs.h>
1.1       root       29: #include <unistd.h>    /* contains read/write */
                     30: #include <fcntl.h>
                     31: 
                     32: #define MINIX_HEADER 32
                     33: #define GCC_HEADER 1024
                     34: 
1.1.1.5   root       35: #define SYS_SIZE 0x4000
1.1.1.3   root       36: 
1.1.1.5   root       37: #define DEFAULT_MAJOR_ROOT 0
                     38: #define DEFAULT_MINOR_ROOT 0
1.1.1.4   root       39: 
1.1.1.2   root       40: /* max nr of sectors of setup: don't change unless you also change
                     41:  * bootsect etc */
                     42: #define SETUP_SECTS 4
                     43: 
                     44: #define STRINGIFY(x) #x
                     45: 
1.1       root       46: void die(char * str)
                     47: {
                     48:        fprintf(stderr,"%s\n",str);
                     49:        exit(1);
                     50: }
                     51: 
                     52: void usage(void)
                     53: {
1.1.1.3   root       54:        die("Usage: build bootsect setup system [rootdev] [> image]");
1.1       root       55: }
                     56: 
                     57: int main(int argc, char ** argv)
                     58: {
                     59:        int i,c,id;
                     60:        char buf[1024];
1.1.1.2   root       61:        char major_root, minor_root;
                     62:        struct stat sb;
1.1       root       63: 
1.1.1.5   root       64:        if ((argc < 4) || (argc > 5))
1.1       root       65:                usage();
1.1.1.4   root       66:        if (argc > 4) {
1.1.1.2   root       67:                if (strcmp(argv[4], "FLOPPY")) {
                     68:                        if (stat(argv[4], &sb)) {
                     69:                                perror(argv[4]);
                     70:                                die("Couldn't stat root device.");
                     71:                        }
                     72:                        major_root = MAJOR(sb.st_rdev);
                     73:                        minor_root = MINOR(sb.st_rdev);
                     74:                } else {
                     75:                        major_root = 0;
                     76:                        minor_root = 0;
                     77:                }
                     78:        } else {
                     79:                major_root = DEFAULT_MAJOR_ROOT;
                     80:                minor_root = DEFAULT_MINOR_ROOT;
                     81:        }
                     82:        fprintf(stderr, "Root device is (%d, %d)\n", major_root, minor_root);
                     83:        if ((major_root != 2) && (major_root != 3) &&
1.1.1.6 ! root       84:            (major_root != 8) && (major_root != 0)) {
1.1.1.2   root       85:                fprintf(stderr, "Illegal root device (major = %d)\n",
                     86:                        major_root);
                     87:                die("Bad root device --- major #");
                     88:        }
1.1       root       89:        for (i=0;i<sizeof buf; i++) buf[i]=0;
                     90:        if ((id=open(argv[1],O_RDONLY,0))<0)
                     91:                die("Unable to open 'boot'");
                     92:        if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)
                     93:                die("Unable to read header of 'boot'");
                     94:        if (((long *) buf)[0]!=0x04100301)
                     95:                die("Non-Minix header of 'boot'");
                     96:        if (((long *) buf)[1]!=MINIX_HEADER)
                     97:                die("Non-Minix header of 'boot'");
                     98:        if (((long *) buf)[3]!=0)
                     99:                die("Illegal data segment in 'boot'");
                    100:        if (((long *) buf)[4]!=0)
                    101:                die("Illegal bss in 'boot'");
                    102:        if (((long *) buf)[5] != 0)
                    103:                die("Non-Minix header of 'boot'");
                    104:        if (((long *) buf)[7] != 0)
                    105:                die("Illegal symbol table in 'boot'");
                    106:        i=read(id,buf,sizeof buf);
                    107:        fprintf(stderr,"Boot sector %d bytes.\n",i);
1.1.1.2   root      108:        if (i != 512)
                    109:                die("Boot block must be exactly 512 bytes");
                    110:        if ((*(unsigned short *)(buf+510)) != 0xAA55)
                    111:                die("Boot block hasn't got boot flag (0xAA55)");
                    112:        buf[508] = (char) minor_root;
                    113:        buf[509] = (char) major_root;   
1.1       root      114:        i=write(1,buf,512);
                    115:        if (i!=512)
                    116:                die("Write call failed");
                    117:        close (id);
                    118:        
                    119:        if ((id=open(argv[2],O_RDONLY,0))<0)
1.1.1.2   root      120:                die("Unable to open 'setup'");
                    121:        if (read(id,buf,MINIX_HEADER) != MINIX_HEADER)
                    122:                die("Unable to read header of 'setup'");
                    123:        if (((long *) buf)[0]!=0x04100301)
                    124:                die("Non-Minix header of 'setup'");
                    125:        if (((long *) buf)[1]!=MINIX_HEADER)
                    126:                die("Non-Minix header of 'setup'");
                    127:        if (((long *) buf)[3]!=0)
                    128:                die("Illegal data segment in 'setup'");
                    129:        if (((long *) buf)[4]!=0)
                    130:                die("Illegal bss in 'setup'");
                    131:        if (((long *) buf)[5] != 0)
                    132:                die("Non-Minix header of 'setup'");
                    133:        if (((long *) buf)[7] != 0)
                    134:                die("Illegal symbol table in 'setup'");
                    135:        for (i=0 ; (c=read(id,buf,sizeof buf))>0 ; i+=c )
                    136:                if (write(1,buf,c)!=c)
                    137:                        die("Write call failed");
                    138:        close (id);
                    139:        if (i > SETUP_SECTS*512)
                    140:                die("Setup exceeds " STRINGIFY(SETUP_SECTS)
                    141:                        " sectors - rewrite build/boot/setup");
                    142:        fprintf(stderr,"Setup is %d bytes.\n",i);
                    143:        for (c=0 ; c<sizeof(buf) ; c++)
                    144:                buf[c] = '\0';
                    145:        while (i<SETUP_SECTS*512) {
                    146:                c = SETUP_SECTS*512-i;
                    147:                if (c > sizeof(buf))
                    148:                        c = sizeof(buf);
                    149:                if (write(1,buf,c) != c)
                    150:                        die("Write call failed");
                    151:                i += c;
                    152:        }
                    153:        
                    154:        if ((id=open(argv[3],O_RDONLY,0))<0)
1.1       root      155:                die("Unable to open 'system'");
                    156:        if (read(id,buf,GCC_HEADER) != GCC_HEADER)
                    157:                die("Unable to read header of 'system'");
                    158:        if (((long *) buf)[5] != 0)
                    159:                die("Non-GCC header of 'system'");
                    160:        for (i=0 ; (c=read(id,buf,sizeof buf))>0 ; i+=c )
                    161:                if (write(1,buf,c)!=c)
                    162:                        die("Write call failed");
                    163:        close(id);
1.1.1.2   root      164:        fprintf(stderr,"System is %d bytes.\n",i);
1.1.1.3   root      165:        if (i > SYS_SIZE*16)
                    166:                die("System is too big");
1.1       root      167:        return(0);
                    168: }

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