nuclear@88: #include <stdio.h>
nuclear@88: #include <stdlib.h>
nuclear@88: #include <assert.h>
nuclear@88: #include "part.h"
nuclear@88: #include "ata.h"
nuclear@88: 
nuclear@88: #define PTYPE_EXT		0x5
nuclear@88: #define PTYPE_EXT_LBA	0xf
nuclear@88: 
nuclear@88: #define PATTR_ACT_BIT	(1 << 9)
nuclear@88: #define PATTR_PRIM_BIT	(1 << 10)
nuclear@88: 
nuclear@88: #define PTYPE(attr)		((attr) & 0xff)
nuclear@88: #define IS_ACT(attr)	((attr) & PATTR_ACT_BIT)
nuclear@88: #define IS_PRIM(attr)	((attr) & PATTR_PRIM_BIT)
nuclear@88: 
nuclear@88: #define BOOTSIG_OFFS	510
nuclear@88: #define PTABLE_OFFS		0x1be
nuclear@88: 
nuclear@88: #define BOOTSIG			0xaa55
nuclear@88: 
nuclear@88: #define IS_MBR			(sidx == 0)
nuclear@88: #define IS_FIRST_EBR	(!IS_MBR && (first_ebr_offs == 0))
nuclear@88: 
nuclear@88: struct part_record {
nuclear@88: 	uint8_t stat;
nuclear@88: 	uint8_t first_head, first_cyl, first_sect;
nuclear@88: 	uint8_t type;
nuclear@88: 	uint8_t last_head, last_cyl, last_sect;
nuclear@88: 	uint32_t first_lba;
nuclear@88: 	uint32_t nsect_lba;
nuclear@88: } __attribute__((packed));
nuclear@88: 
nuclear@88: 
nuclear@88: static uint16_t bootsig(const char *sect);
nuclear@88: 
nuclear@88: 
nuclear@88: struct partition *get_part_list(int devno)
nuclear@88: {
nuclear@88: 	char *sect;
nuclear@88: 	struct partition *phead = 0, *ptail = 0;
nuclear@88: 	uint32_t sidx = 0;
nuclear@88: 	uint32_t first_ebr_offs = 0;
nuclear@88: 	int i, num_bootrec = 0;
nuclear@88: 
nuclear@88: 	sect = malloc(512);
nuclear@88: 	assert(sect);
nuclear@88: 
nuclear@88: 	do {
nuclear@88: 		int num_rec;
nuclear@88: 		struct part_record *prec;
nuclear@88: 
nuclear@88: 		if(IS_FIRST_EBR) {
nuclear@88: 			first_ebr_offs = sidx;
nuclear@88: 		}
nuclear@88: 
nuclear@88: 		if(ata_read_pio(devno, sidx, sect) == -1) {
nuclear@88: 			goto err;
nuclear@88: 		}
nuclear@88: 		if(bootsig(sect) != BOOTSIG) {
nuclear@88: 			printf("invalid/corrupted partition table, sector %lu has no magic\n", (unsigned long)sidx);
nuclear@88: 			goto err;
nuclear@88: 		}
nuclear@88: 		prec = (struct part_record*)(sect + PTABLE_OFFS);
nuclear@88: 
nuclear@88: 		/* MBR has 4 records, EBRs have 2 */
nuclear@88: 		num_rec = IS_MBR ? 4 : 2;
nuclear@88: 
nuclear@88: 		for(i=0; i<num_rec; i++) {
nuclear@88: 			struct partition *pnode;
nuclear@88: 
nuclear@88: 			/* ignore empty partitions in the MBR, stop if encountered in an EBR */
nuclear@88: 			if(prec[i].type == 0) {
nuclear@88: 				if(num_bootrec > 0) {
nuclear@88: 					sidx = 0;
nuclear@88: 					break;
nuclear@88: 				}
nuclear@88: 				continue;
nuclear@88: 			}
nuclear@88: 
nuclear@88: 			/* ignore extended partitions and setup sector index to read
nuclear@88: 			 * the next logical partition afterwards.
nuclear@88: 			 */
nuclear@88: 			if(prec[i].type == PTYPE_EXT || prec[i].type == PTYPE_EXT_LBA) {
nuclear@88: 				/* all EBR start fields are relative to the first EBR offset */
nuclear@88: 				sidx = first_ebr_offs + prec[i].first_lba;
nuclear@88: 				continue;
nuclear@88: 			}
nuclear@88: 
nuclear@88: 			pnode = malloc(sizeof *pnode);
nuclear@88: 			assert(pnode);
nuclear@88: 
nuclear@88: 			pnode->attr = prec[i].type;
nuclear@88: 
nuclear@88: 			if(prec[i].stat & 0x80) {
nuclear@88: 				pnode->attr |= PATTR_ACT_BIT;
nuclear@88: 			}
nuclear@88: 			if(IS_MBR) {
nuclear@88: 				pnode->attr |= PATTR_PRIM_BIT;
nuclear@88: 			}
nuclear@88: 			pnode->start_sect = prec[i].first_lba + first_ebr_offs;
nuclear@88: 			pnode->size_sect = prec[i].nsect_lba;
nuclear@88: 			pnode->next = 0;
nuclear@88: 
nuclear@88: 			/* append to the list */
nuclear@88: 			if(!phead) {
nuclear@88: 				phead = ptail = pnode;
nuclear@88: 			} else {
nuclear@88: 				ptail->next = pnode;
nuclear@88: 				ptail = pnode;
nuclear@88: 			}
nuclear@88: 		}
nuclear@88: 
nuclear@88: 		num_bootrec++;
nuclear@88: 	} while(sidx > 0);
nuclear@88: 
nuclear@88: 	free(sect);
nuclear@88: 	return phead;
nuclear@88: 
nuclear@88: err:
nuclear@88: 	free(sect);
nuclear@88: 	while(phead) {
nuclear@88: 		void *tmp = phead;
nuclear@88: 		phead = phead->next;
nuclear@88: 		free(tmp);
nuclear@88: 	}
nuclear@88: 	return 0;
nuclear@88: }
nuclear@88: 
nuclear@88: void free_part_list(struct partition *plist)
nuclear@88: {
nuclear@88: 	while(plist) {
nuclear@88: 		struct partition *tmp = plist;
nuclear@88: 		plist = plist->next;
nuclear@88: 		free(tmp);
nuclear@88: 	}
nuclear@88: }
nuclear@88: 
nuclear@88: int get_part_type(struct partition *p)
nuclear@88: {
nuclear@88: 	return PTYPE(p->attr);
nuclear@88: }
nuclear@88: 
nuclear@88: 
nuclear@88: static uint16_t bootsig(const char *sect)
nuclear@88: {
nuclear@88: 	return *(uint16_t*)(sect + BOOTSIG_OFFS);
nuclear@88: }
nuclear@88: