/* $OpenBSD: mbr.c,v 1.119 2022/04/25 17:10:09 krw Exp $ */ /* * Copyright (c) 1997 Tobias Weingartner * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include /* DEV_BSIZE */ #include #include #include #include #include #include #include #include "part.h" #include "disk.h" #include "misc.h" #include "mbr.h" #include "gpt.h" struct dos_mbr default_dmbr; void mbr_to_dos_mbr(const struct mbr *, struct dos_mbr *); void dos_mbr_to_mbr(const struct dos_mbr *, const uint64_t, const uint64_t, struct mbr *); void MBR_init(struct mbr *mbr) { struct dos_partition dp; struct prt bootprt, obsdprt; daddr_t daddr; memset(&gmbr, 0, sizeof(gmbr)); memset(&gh, 0, sizeof(gh)); memset(&gp, 0, sizeof(gp)); if (mbr->mbr_lba_self != 0) { /* Extended MBR - save lba's, set sig, zap everything else. */ memset(mbr->mbr_code, 0, sizeof(mbr->mbr_code)); memset(mbr->mbr_prt, 0, sizeof(mbr->mbr_prt)); mbr->mbr_signature = DOSMBR_SIGNATURE; return; } memset(&obsdprt, 0, sizeof(obsdprt)); memset(&bootprt, 0, sizeof(bootprt)); if (disk.dk_bootprt.prt_ns > 0) { bootprt = disk.dk_bootprt; } else { memcpy(&dp, &default_dmbr.dmbr_parts[0], sizeof(dp)); PRT_parse(&dp, 0, 0, &bootprt); } if (bootprt.prt_ns > 0) { /* Start OpenBSD partition immediately after bootprt. */ obsdprt.prt_bs = bootprt.prt_bs + bootprt.prt_ns; } else if (disk.dk_heads > 1 || disk.dk_cylinders > 1) { /* * Start OpenBSD partition on power of 2 block number * after the first track. */ daddr = 1; while (daddr < DL_SECTOBLK(&dl, disk.dk_sectors)) daddr *= 2; obsdprt.prt_bs = DL_BLKTOSEC(&dl, daddr); } else { /* Start OpenBSD partition immediately after MBR. */ obsdprt.prt_bs = 1; } if (obsdprt.prt_bs >= disk.dk_size) { memset(&obsdprt, 0, sizeof(obsdprt)); } else { obsdprt.prt_ns = disk.dk_size - obsdprt.prt_bs; obsdprt.prt_id = DOSPTYP_OPENBSD; if (bootprt.prt_flag != DOSACTIVE) obsdprt.prt_flag = DOSACTIVE; } memset(mbr, 0, sizeof(*mbr)); memcpy(mbr->mbr_code, default_dmbr.dmbr_boot, sizeof(mbr->mbr_code)); mbr->mbr_prt[0] = bootprt; mbr->mbr_prt[3] = obsdprt; mbr->mbr_signature = DOSMBR_SIGNATURE; } void dos_mbr_to_mbr(const struct dos_mbr *dmbr, const uint64_t lba_self, const uint64_t lba_firstembr, struct mbr *mbr) { struct dos_partition dos_parts[NDOSPART]; int i; memcpy(mbr->mbr_code, dmbr->dmbr_boot, sizeof(mbr->mbr_code)); mbr->mbr_lba_self = lba_self; mbr->mbr_lba_firstembr = lba_firstembr; mbr->mbr_signature = letoh16(dmbr->dmbr_sign); memcpy(dos_parts, dmbr->dmbr_parts, sizeof(dos_parts)); for (i = 0; i < NDOSPART; i++) PRT_parse(&dos_parts[i], lba_self, lba_firstembr, &mbr->mbr_prt[i]); } void mbr_to_dos_mbr(const struct mbr *mbr, struct dos_mbr *dos_mbr) { struct dos_partition dos_partition; int i; memcpy(dos_mbr->dmbr_boot, mbr->mbr_code, sizeof(dos_mbr->dmbr_boot)); dos_mbr->dmbr_sign = htole16(DOSMBR_SIGNATURE); for (i = 0; i < NDOSPART; i++) { PRT_make(&mbr->mbr_prt[i], mbr->mbr_lba_self, mbr->mbr_lba_firstembr, &dos_partition); memcpy(&dos_mbr->dmbr_parts[i], &dos_partition, sizeof(dos_mbr->dmbr_parts[i])); } } void MBR_print(const struct mbr *mbr, const char *units) { int i; DISK_printgeometry("s"); printf("Offset: %llu\t", mbr->mbr_lba_self); printf("Signature: 0x%X\n", (int)mbr->mbr_signature); PRT_print_parthdr(); for (i = 0; i < NDOSPART; i++) PRT_print_part(i, &mbr->mbr_prt[i], units); } int MBR_read(const uint64_t lba_self, const uint64_t lba_firstembr, struct mbr *mbr) { struct dos_mbr dos_mbr; if (DISK_readbytes(&dos_mbr, lba_self, sizeof(dos_mbr))) return -1; dos_mbr_to_mbr(&dos_mbr, lba_self, lba_firstembr, mbr); return 0; } int MBR_write(const struct mbr *mbr) { struct dos_mbr dos_mbr; mbr_to_dos_mbr(mbr, &dos_mbr); if (DISK_writebytes(&dos_mbr, mbr->mbr_lba_self, sizeof(dos_mbr))) return -1; /* Refresh in-kernel disklabel from the updated disk information. */ if (ioctl(disk.dk_fd, DIOCRLDINFO, 0) == -1) warn("DIOCRLDINFO"); return 0; }