xenix redux (or, how to bring back a dead xenix pc)

Cameron Kaiser wrote: no problem. it was just a quick hack. --- cut here --- #include <stdio.h> #include <fcntl.h> #define __packed2__ __attribute__ ((packed, aligned(2))) typedef unsigned short u16; typedef unsigned int u32; typedef short s16; typedef int s32; typedef u16 sysv_ino_t; typedef u32 sysv_zone_t; /* Xenix super-block data on disk */ #define XENIX_NICINOD 100 /* number of inode cache entries */ #define XENIX_NICFREE 100 /* number of free block list chunk entries */ struct xenix_super_block { u16 s_isize; /* index of first data zone */ u32 s_fsize __packed2__; /* total number of zones of this fs */ /* the start of the free block list: */ u16 s_nfree; /* number of free blocks in s_free, <= XENIX_NICFREE */ u32 s_free[XENIX_NICFREE]; /* first free block list chunk */ /* the cache of free inodes: */ u16 s_ninode; /* number of free inodes in s_inode, <= XENIX_NICINOD */ sysv_ino_t s_inode[XENIX_NICINOD]; /* some free inodes */ /* locks, not used by Linux: */ char s_flock; /* lock during free block list manipulation */ char s_ilock; /* lock during inode cache manipulation */ char s_fmod; /* super-block modified flag */ char s_ronly; /* flag whether fs is mounted read-only */ u32 s_time __packed2__; /* time of last super block update */ u32 s_tfree __packed2__; /* total number of free zones */ u16 s_tinode; /* total number of free inodes */ s16 s_dinfo[4]; /* device information ?? */ char s_fname[6]; /* file system volume name */ char s_fpack[6]; /* file system pack name */ char s_clean; /* set to 0x46 when filesystem is properly unmounted */ char s_fill[371]; s32 s_magic; /* version of file system */ s32 s_type; /* type of file system: 1 for 512 byte blocks 2 for 1024 byte blocks 3 for 2048 byte blocks */ }; char buffer[4096]; main() { int fd, ret; struct xenix_super_block *sb; int offset; fd = open("d1", O_RDONLY); sb = (struct xenix_super_block *)buffer; printf("size %d\n", sizeof(struct xenix_super_block)); //printf("offset %d\n", ((char *)&sb->s_magic) - buffer); offset = 0; while (1) { ret = read(fd, buffer, 1024); if (ret != 1024) break; if (sb->s_magic == 0x002b5544 && (sb->s_type >= 1 && sb->s_type <= 3)) { printf("offset %d 0x%x\n", offset, offset); printf("block %d\n", (offset-1024) / 512); printf("s_magic %08x\n", sb->s_magic); printf("s_type %08x\n", sb->s_type); printf("s_nfree %04x\n", sb->s_nfree); } offset += 1024; } }