diff options
Diffstat (limited to 'com32/chain/utility.c')
| -rw-r--r-- | com32/chain/utility.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/com32/chain/utility.c b/com32/chain/utility.c new file mode 100644 index 0000000..b17997f --- /dev/null +++ b/com32/chain/utility.c @@ -0,0 +1,256 @@ +/* ----------------------------------------------------------------------- * + * + * Copyright 2003-2009 H. Peter Anvin - All Rights Reserved + * Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin + * Copyright 2010 Shao Miller + * Copyright 2010-2012 Michal Soltys + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, + * copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom + * the Software is furnished to do so, subject to the following + * conditions: + * + * The above copyright notice and this permission notice shall + * be included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * ----------------------------------------------------------------------- */ + +#include <com32.h> +#include <fcntl.h> +#include <stdint.h> +#include <stdio.h> +#include <errno.h> +#include <unistd.h> +#include <string.h> +#include <fs.h> +#include <syslinux/disk.h> +#include <syslinux/pmapi.h> +#include "utility.h" + +static const char *bpbtypes[] = { + [0] = "unknown", + [1] = "2.0", + [2] = "3.0", + [3] = "3.2", + [4] = "3.4", + [5] = "4.0", + [6] = "8.0 (NT+)", + [7] = "7.0", + [8] = "exFAT", +}; + +void wait_key(void) +{ + int cnt; + char junk; + + /* drain */ + do { + errno = 0; + cnt = read(0, &junk, 1); + } while (cnt > 0 || (cnt < 0 && errno == EAGAIN)); + + /* wait */ + do { + errno = 0; + cnt = read(0, &junk, 1); + } while (!cnt || (cnt < 0 && errno == EAGAIN)); +} + +int guid_is0(const struct guid *guid) +{ + return + !(guid->data1 || + guid->data2 || + guid->data3 || + guid->data4); +} + +/* + * mode explanation: + * + * cnul - "strict" mode, never returning higher value than obtained from cbios + * cadd - if the disk is larger than reported geometry /and/ if the geometry has + * less cylinders than 1024 - it means that the total size is somewhere + * between cs and cs+1; in this particular case, we bump the cs to be able + * to return matching chs triplet + * cmax - assume we can use any cylinder value + * + * by default cadd seems most reasonable, giving consistent results with e.g. + * sfdisk's behavior + */ +void lba2chs(disk_chs *dst, const struct disk_info *di, uint64_t lba, int mode) +{ + uint32_t c, h, s, t; + uint32_t cs, hs, ss; + + /* + * Not much reason here, but if we have no valid CHS geometry, we assume + * "typical" ones to have something to return. + */ + if (di->cbios) { + cs = di->cyl; + hs = di->head; + ss = di->spt; + if (mode == L2C_CADD) { + if (cs < 1024 && di->lbacnt > cs*hs*ss) + cs++; + } else if (mode == L2C_CMAX) + cs = 1024; + } else { + if (di->disk & 0x80) { + cs = 1024; + hs = 255; + ss = 63; + } else { + cs = 80; + hs = 2; + ss = 18; + } + } + + if (lba >= cs*hs*ss) { + s = ss; + h = hs - 1; + c = cs - 1; + } else { + s = (lba % ss) + 1; + t = lba / ss; + h = t % hs; + c = t / hs; + } + + (*dst)[0] = h; + (*dst)[1] = s | ((c & 0x300) >> 2); + (*dst)[2] = c; +} + +uint32_t get_file_lba(const char *filename) +{ + struct com32_filedata fd; + uint32_t lba = 0; + int size = 65536; + char *buf; + + buf = lmalloc(size); + if (!buf) + return 0; + + /* Put the filename in the bounce buffer */ + strlcpy(buf, filename, size); + + if (open_file(buf, O_RDONLY, &fd) <= 0) { + goto fail; /* Filename not found */ + } + + /* Since the first member is the LBA, we simply cast */ + lba = *((uint32_t *) MK_PTR(0, fd.handle)); + + /* Call comapi_close() to free the structure */ + close_file(fd.handle); + +fail: + lfree(buf); + return lba; +} + +/* drive offset detection */ +int drvoff_detect(int type) +{ + if (bpbV40 <= type && type <= bpbVNT) { + return 0x24; + } else if (type == bpbV70) { + return 0x40; + } else if (type == bpbEXF) { + return 0x6F; + } + + return -1; +} + +/* + * heuristics could certainly be improved + */ +int bpb_detect(const uint8_t *sec, const char *tag) +{ + int a, b, c, jmp = -1, rev = 0; + + /* exFAT mess first (media descriptor is 0 here) */ + if (!memcmp(sec + 0x03, "EXFAT ", 8)) { + rev = bpbEXF; + goto out; + } + + /* media descriptor check */ + if ((sec[0x15] & 0xF0) != 0xF0) + goto out; + + if (sec[0] == 0xEB) /* jump short */ + jmp = 2 + *(int8_t *)(sec + 1); + else if (sec[0] == 0xE9) /* jump near */ + jmp = 3 + *(int16_t *)(sec + 1); + + if (jmp < 0) /* no boot code at all ? */ + goto nocode; + + /* sanity */ + if (jmp < 0x18 || jmp > 0x1F0) + goto out; + + /* detect by jump */ + if (jmp >= 0x18 && jmp < 0x1E) + rev = bpbV20; + else if (jmp >= 0x1E && jmp < 0x20) + rev = bpbV30; + else if (jmp >= 0x20 && jmp < 0x24) + rev = bpbV32; + else if (jmp >= 0x24 && jmp < 0x46) + rev = bpbV34; + + /* TODO: some better V2 - V3.4 checks ? */ + + if (rev) + goto out; + /* + * BPB info: + * 2.0 == 0x0B - 0x17 + * 3.0 == 2.0 + 0x18 - 0x1D + * 3.2 == 3.0 + 0x1E - 0x1F + * 3.4 ==!2.0 + 0x18 - 0x23 + * 4.0 == 3.4 + 0x24 - 0x45 + * NT ==~3.4 + 0x24 - 0x53 + * 7.0 == 3.4 + 0x24 - 0x59 + */ + +nocode: + a = memcmp(sec + 0x03, "NTFS", 4); + b = memcmp(sec + 0x36, "FAT", 3); + c = memcmp(sec + 0x52, "FAT", 3); /* ext. DOS 7+ bs */ + + if ((sec[0x26] & 0xFE) == 0x28 && !b) { + rev = bpbV40; + } else if (sec[0x26] == 0x80 && !a) { + rev = bpbVNT; + } else if ((sec[0x42] & 0xFE) == 0x28 && !c) { + rev = bpbV70; + } + +out: + printf("BPB detection (%s): %s\n", tag, bpbtypes[rev]); + return rev; +} + +/* vim: set ts=8 sts=4 sw=4 noet: */ |