ref: 1a5fc6fcd59fe507cdfef2628de0d6bdddb25cea
parent: 7180b70ad36a7db3aadfa74fbca1555a91df5da1
author: ment <[email protected]>
date: Wed Jun 8 19:05:44 EDT 2011
unix/mbrfix: no longer needed
--- a/sys/src/cmd/unix/mbrfix.c
+++ /dev/null
@@ -1,196 +1,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <stdarg.h>
-#include <sys/types.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <string.h>
-
-typedef unsigned char uchar;
-typedef unsigned int uint;
-typedef unsigned long long vlong;
-
-
-enum {- Sectsz = 0x200,
- Psectsz = 11,
- Pclustsc = 13,
- Presvd = 14,
- Pnumfat = 16,
- Pfatsz = 22,
- Pfatsz32 = 36,
- Pvolid = 67,
-};
-
-int
-readn(int f, void *av, int n)
-{- char *a;
- int m, t;
- a = av;
- t = 0;
- while(t < n){- m = read(f, a+t, n-t);
- if(m <= 0){- if(t == 0)
- return m;
- break;
- }
- t += m;
- }
- return t;
-}
-
-void
-sysfatal(char *fmt, ...)
-{- va_list va;
- va_start(va, fmt);
- vfprintf(stderr, fmt, va);
- va_end(va);
- fprintf(stderr, "\n");
- exit(1);
-}
-
-void
-readsect(int fd, uint n, void *data)
-{- loff_t off;
-
- off = (loff_t) n * Sectsz;
- if(llseek(fd, off, SEEK_SET) != off)
- sysfatal("seek to sector 0x%x failed", n);- if(readn(fd, data, Sectsz) != Sectsz)
- sysfatal("short read: %m");-}
-
-void
-writesect(int fd, uint n, void *data)
-{- loff_t off;
-
- off = (loff_t) n * Sectsz;
- if(llseek(fd, off, SEEK_SET) != off)
- sysfatal("seek to sector 0x%x failed", n);- if(write(fd, data, Sectsz) != Sectsz)
- sysfatal("short write: %m");-}
-
-uint
-getulong(uchar *s)
-{- return s[0] | (s[1] << 8) | (s[2] << 16) | (s[3] << 24);
-}
-
-void
-putulong(uchar *s, uint n)
-{- *s++ = n & 0xff;
- *s++ = (n >> 8) & 0xff;
- *s++ = (n >> 16) & 0xff;
- *s++ = (n >> 24) & 0xff;
-}
-
-
-uint
-getushort(uchar *s)
-{- return s[0] | (s[1] << 8);
-}
-
-int
-checksig(uchar *s)
-{- return s[0x1fe] == 0x55 && s[0x1ff] == 0xaa;
-}
-
-void
-fixpbs(uchar *pbs, uchar *pbs9, uint lba)
-{- uint a;
- uint fatsz, resvd, numfat;
-
- numfat = pbs[Pnumfat];
- fatsz = getushort(&pbs[Pfatsz]);
- if(fatsz == 0)
- fatsz = getulong(&pbs[Pfatsz32]);
- resvd = getushort(&pbs[Presvd]);
-
- a = pbs9[1] + 2;
- memcpy(pbs, pbs9, 3);
- memcpy(pbs+a, pbs9+a, Sectsz-a-2);
- a = lba + numfat * fatsz + resvd;
- printf("Xroot=%x\n", a);- putulong(&pbs[Pvolid], a);
-}
-
-
-int
-main(int argc, char *argv[])
-{- int dev, fd, i;
- uchar mbr9[Sectsz], pbs9[Sectsz];
- uchar mbr[Sectsz], pbs[Sectsz];
- uint lba;
- int part, want;
- char *mbrfn, *pbsfn, *devfn;
-
- if(argc < 4)
- sysfatal("usage: <device> <mbrfile> <pbsfile> [part]");- devfn = argv[1];
- mbrfn = argv[2];
- pbsfn = argv[3];
- want = argc >= 5 ? atoi(argv[4]) : -1;
- part = -1;
-
- dev = open(devfn, O_RDWR);
- if(dev < 0)
- sysfatal("%s: %m", devfn);-
- if((fd = open(mbrfn, O_RDONLY)) < 0)
- sysfatal("%s: %m", mbrfn);- if(readn(fd, mbr9, Sectsz) < 3)
- sysfatal("%s: too short", mbrfn);- close(fd);
-
- fd = open(pbsfn, O_RDONLY);
- if(fd < 0)
- sysfatal("%s: %m", pbsfn);- if(readn(fd, pbs9, Sectsz) < 3)
- sysfatal("%s: too short", pbsfn);- if(pbs9[0] != 0xeb)
- sysfatal("first byte of pbs not a short jump");- close(fd);
-
- readsect(dev, 0, mbr);
- if(!checksig(mbr))
- sysfatal("sector 0 is missing signature");- for(i=0; i<4; i++){- if(mbr[0x1be + i*16] == 0x80 && (part == -1 || i == want))
- part = i;
- }
- if(part == -1)
- sysfatal("no bootable partitions found");- if(want != -1 && part != want)
- sysfatal("partition %d is not bootable", want);-
- lba = getulong(&mbr[0x1be + part*16 + 8]);
- if(lba == 0)
- sysfatal("partition %d has zero LBA", part);-
- readsect(dev, lba, pbs);
- if(!checksig(pbs))
- sysfatal("partition %d (LBA=0x%x) is missing signaure", part, lba);- if(getushort(&pbs[Psectsz]) != 512)
- sysfatal("sector size not 512");-
- printf("using partition %d, LBA=0x%x\n", part, lba);- memcpy(mbr, mbr9, 446);
- fixpbs(pbs, pbs9, lba);
-
- writesect(dev, 0, mbr);
- writesect(dev, lba, pbs);
-
- close(dev);
- return 0;
-}