diff options
| -rw-r--r-- | sys/arch/amd64/stand/efiboot/efidev.c | 73 |
1 files changed, 56 insertions, 17 deletions
diff --git a/sys/arch/amd64/stand/efiboot/efidev.c b/sys/arch/amd64/stand/efiboot/efidev.c index 00f48626720..034bb4f21a3 100644 --- a/sys/arch/amd64/stand/efiboot/efidev.c +++ b/sys/arch/amd64/stand/efiboot/efidev.c @@ -1,4 +1,4 @@ -/* $OpenBSD: efidev.c,v 1.9 2015/11/28 13:50:11 yasuoka Exp $ */ +/* $OpenBSD: efidev.c,v 1.10 2015/11/28 22:53:38 krw Exp $ */ /* * Copyright (c) 1996 Michael Shalayeff @@ -63,6 +63,7 @@ static EFI_STATUS static int efid_diskio(int, struct diskinfo *, u_int, int, void *); static u_int findopenbsd(efi_diskinfo_t, const char **); static uint64_t findopenbsd_gpt(efi_diskinfo_t, const char **); +static int gpt_chk_mbr(struct dos_partition *, efi_diskinfo_t); void efid_init(struct diskinfo *dip, void *handle) @@ -160,6 +161,45 @@ efid_diskio(int rw, struct diskinfo *dip, u_int off, int nsect, void *buf) } /* + * Returns 0 if the MBR with the provided partition array is a GPT protective + * MBR, and returns 1 otherwise. A GPT protective MBR would have one and only + * one MBR partition, an EFI partition that either covers the whole disk or as + * much of it as is possible with a 32bit size field. + * + * Taken from kern/subr_disk.c. + * + * NOTE: MS always uses a size of UINT32_MAX for the EFI partition!** + */ +int +gpt_chk_mbr(struct dos_partition *dp, efi_diskinfo_t ed) +{ + struct dos_partition *dp2; + EFI_LBA dsize; + int efi, found, i; + u_int32_t psize; + + found = efi = 0; + for (dp2=dp, i=0; i < NDOSPART; i++, dp2++) { + if (dp2->dp_typ == DOSPTYP_UNUSED) + continue; + found++; + if (dp2->dp_typ != DOSPTYP_EFI) + continue; + dsize = ed->blkio->Media->LastBlock + 1; + psize = letoh32(dp2->dp_size); + if (psize == (dsize - 1) || + psize == UINT32_MAX) { + if (letoh32(dp2->dp_start) == 1) + efi++; + } + } + if (found == 1 && efi == 1) + return (0); + + return (1); +} + +/* * Try to read the bsd label on the given BIOS device. */ static u_int @@ -168,9 +208,10 @@ findopenbsd(efi_diskinfo_t ed, const char **err) EFI_STATUS status; struct dos_mbr mbr; struct dos_partition *dp; + uint64_t gptoff; u_int mbroff = DOSBBSECTOR; u_int mbr_eoff = DOSBBSECTOR; /* Offset of MBR extended partition. */ - int i, maxebr = DOS_MAXEBR, nextebr, gpt = 0, npart = 0; + int i, maxebr = DOS_MAXEBR, nextebr; again: if (!maxebr--) { @@ -192,13 +233,24 @@ again: return (-1); } + /* check for GPT protective MBR. */ + if (mbroff == DOSBBSECTOR && gpt_chk_mbr(mbr.dmbr_parts, ed) == 0) { + gptoff = findopenbsd_gpt(ed, err); + if (gptoff > UINT_MAX || EFI_SECTOBLK(ed, gptoff) > UINT_MAX) { + *err = "Paritition LBA > 2**32"; + return (-1); + } + if (gptoff == -1) + return (-1); + return EFI_SECTOBLK(ed, gptoff); + } + /* Search for OpenBSD partition */ nextebr = 0; for (i = 0; i < NDOSPART; i++) { dp = &mbr.dmbr_parts[i]; - if (!dp->dp_size || dp->dp_typ == DOSPTYP_UNUSED) + if (!dp->dp_size) continue; - npart++; #ifdef BIOS_DEBUG if (debug) printf("found partition %u: " @@ -225,25 +277,12 @@ again: if (mbr_eoff == DOSBBSECTOR) mbr_eoff = dp->dp_start; } - - if (dp->dp_typ == DOSPTYP_EFI) - gpt++; } if (nextebr && nextebr != (u_int)-1) { mbroff = nextebr; goto again; } - if (gpt == 1 && npart == 1) { - uint64_t gptoff = findopenbsd_gpt(ed, err); - if (gptoff > UINT_MAX || EFI_SECTOBLK(ed, gptoff) > UINT_MAX) { - *err = "Paritition LBA > 2**32"; - return (-1); - } - if (gptoff == -1) - return (-1); - return EFI_SECTOBLK(ed, gptoff); - } return (-1); } |