kern
annotate src/fs.c @ 89:2f555c81ae67
starting the filesystem
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Thu, 08 Dec 2011 18:19:35 +0200 |
| parents | a398bf73fe93 |
| children | 7ff2b4971216 |
| rev | line source |
|---|---|
| nuclear@88 | 1 #include <stdio.h> |
| nuclear@89 | 2 #include <stdlib.h> |
| nuclear@89 | 3 #include <assert.h> |
| nuclear@88 | 4 #include "fs.h" |
| nuclear@88 | 5 #include "ata.h" |
| nuclear@88 | 6 #include "part.h" |
| nuclear@88 | 7 #include "panic.h" |
| nuclear@88 | 8 |
| nuclear@89 | 9 #define MAGIC 0xccf5ccf5 |
| nuclear@89 | 10 #define BLKSZ 1024 |
| nuclear@88 | 11 |
| nuclear@89 | 12 typedef uint32_t blkid; |
| nuclear@89 | 13 |
| nuclear@89 | 14 struct superblock { |
| nuclear@89 | 15 uint32_t magic; |
| nuclear@89 | 16 |
| nuclear@89 | 17 blkid istart; |
| nuclear@89 | 18 unsigned int icount; |
| nuclear@89 | 19 |
| nuclear@89 | 20 blkid dstart; |
| nuclear@89 | 21 unsigned int dcount; |
| nuclear@89 | 22 }; |
| nuclear@89 | 23 |
| nuclear@89 | 24 struct filesys { |
| nuclear@89 | 25 int dev; |
| nuclear@89 | 26 struct partition part; |
| nuclear@89 | 27 |
| nuclear@89 | 28 struct superblock *sb; |
| nuclear@89 | 29 }; |
| nuclear@89 | 30 |
| nuclear@89 | 31 static int find_rootfs(struct filesys *fs); |
| nuclear@88 | 32 |
| nuclear@88 | 33 /* root device & partition */ |
| nuclear@89 | 34 static struct filesys root; |
| nuclear@88 | 35 |
| nuclear@88 | 36 void init_fs(void) |
| nuclear@88 | 37 { |
| nuclear@89 | 38 root.sb = malloc(512); |
| nuclear@89 | 39 assert(root.sb); |
| nuclear@89 | 40 |
| nuclear@89 | 41 if(find_rootfs(&root) == -1) { |
| nuclear@88 | 42 panic("can't find root filesystem\n"); |
| nuclear@88 | 43 } |
| nuclear@88 | 44 } |
| nuclear@88 | 45 |
| nuclear@89 | 46 #define PART_TYPE 0xcc |
| nuclear@89 | 47 static int find_rootfs(struct filesys *fs) |
| nuclear@88 | 48 { |
| nuclear@88 | 49 int i, num_dev, partid; |
| nuclear@88 | 50 struct partition *plist, *p; |
| nuclear@88 | 51 |
| nuclear@88 | 52 num_dev = ata_num_devices(); |
| nuclear@88 | 53 for(i=0; i<num_dev; i++) { |
| nuclear@88 | 54 plist = p = get_part_list(i); |
| nuclear@88 | 55 |
| nuclear@88 | 56 partid = 0; |
| nuclear@88 | 57 while(p) { |
| nuclear@88 | 58 if(get_part_type(p) == PART_TYPE) { |
| nuclear@89 | 59 /* found the correct partition, now read the superblock |
| nuclear@89 | 60 * and make sure it's got the correct magic id |
| nuclear@89 | 61 */ |
| nuclear@89 | 62 ata_read_pio(i, p->start_sect + 2, fs->sb); |
| nuclear@89 | 63 |
| nuclear@89 | 64 if(fs->sb->magic == MAGIC) { |
| nuclear@89 | 65 printf("found root ata%dp%d\n", i, partid); |
| nuclear@89 | 66 fs->dev = i; |
| nuclear@89 | 67 fs->part = *p; |
| nuclear@89 | 68 return 0; |
| nuclear@89 | 69 } |
| nuclear@88 | 70 } |
| nuclear@88 | 71 p = p->next; |
| nuclear@88 | 72 partid++; |
| nuclear@88 | 73 } |
| nuclear@88 | 74 free_part_list(plist); |
| nuclear@88 | 75 } |
| nuclear@88 | 76 return -1; |
| nuclear@88 | 77 } |