1 /* ----------------------------------------------------------------------- * 2 * 3 * Copyright 2009 Pierre-Alexandre Meyer 4 * 5 * Some parts borrowed from chain.c32: 6 * 7 * Copyright 2003-2009 H. Peter Anvin - All Rights Reserved 8 * Copyright 2009 Intel Corporation; author: H. Peter Anvin 9 * 10 * This file is part of Syslinux, and is made available under 11 * the terms of the GNU General Public License version 2. 12 * 13 * ----------------------------------------------------------------------- */ 14 15 #include <com32.h> 16 #include <stdlib.h> 17 #include <string.h> 18 19 #include <disk/common.h> 20 #include <disk/errno_disk.h> 21 #include <disk/read.h> 22 #include <disk/util.h> 23 #include <disk/write.h> 24 25 /** 26 * write_sectors - write several sectors from disk 27 * @drive_info: driveinfo struct describing the disk 28 * @lba: Position to write 29 * @data: Buffer to write 30 * @size: Size of the buffer (number of sectors) 31 * 32 * Return the number of sectors write on success or -1 on failure. 33 * errno_disk contains the error number. 34 **/ 35 int write_sectors(const struct driveinfo *drive_info, const unsigned int lba, 36 const void *data, const int size) 37 { 38 com32sys_t inreg, outreg; 39 struct ebios_dapa *dapa; 40 void *buf; 41 int rv = -1; 42 43 buf = lmalloc(size); 44 if (!buf) 45 return -1; 46 47 dapa = lmalloc(sizeof(*dapa)); 48 if (!dapa) 49 goto out; 50 51 memcpy(buf, data, size); 52 memset(&inreg, 0, sizeof inreg); 53 54 if (drive_info->ebios) { 55 dapa->len = sizeof(*dapa); 56 dapa->count = size; 57 dapa->off = OFFS(buf); 58 dapa->seg = SEG(buf); 59 dapa->lba = lba; 60 61 inreg.esi.w[0] = OFFS(dapa); 62 inreg.ds = SEG(dapa); 63 inreg.edx.b[0] = drive_info->disk; 64 inreg.eax.w[0] = 0x4300; /* Extended write */ 65 } else { 66 unsigned int c, h, s; 67 68 if (!drive_info->cbios) { // XXX errno 69 /* We failed to get the geometry */ 70 if (lba) 71 goto out; /* Can only write MBR */ 72 73 s = 1; 74 h = 0; 75 c = 0; 76 } else 77 lba_to_chs(drive_info, lba, &s, &h, &c); 78 79 // XXX errno 80 if (s > 63 || h > 256 || c > 1023) 81 goto out; 82 83 inreg.eax.w[0] = 0x0301; /* Write one sector */ 84 inreg.ecx.b[1] = c & 0xff; 85 inreg.ecx.b[0] = s + (c >> 6); 86 inreg.edx.b[1] = h; 87 inreg.edx.b[0] = drive_info->disk; 88 inreg.ebx.w[0] = OFFS(buf); 89 inreg.es = SEG(buf); 90 } 91 92 /* Perform the write */ 93 if (int13_retry(&inreg, &outreg)) { 94 errno_disk = outreg.eax.b[1]; /* Give up */ 95 } else 96 rv = size; 97 out: 98 lfree(dapa); 99 lfree(buf); 100 return rv; 101 } 102 103 /** 104 * write_verify_sectors - write several sectors from disk 105 * @drive_info: driveinfo struct describing the disk 106 * @lba: Position to write 107 * @data: Buffer to write 108 **/ 109 int write_verify_sector(struct driveinfo *drive_info, 110 const unsigned int lba, const void *data) 111 { 112 return write_verify_sectors(drive_info, lba, data, SECTOR); 113 } 114 115 /** 116 * write_verify_sectors - write several sectors from disk 117 * @drive_info: driveinfo struct describing the disk 118 * @lba: Position to write 119 * @data: Buffer to write 120 * @size: Size of the buffer (number of sectors) 121 **/ 122 int write_verify_sectors(struct driveinfo *drive_info, 123 const unsigned int lba, 124 const void *data, const int size) 125 { 126 char *rb = malloc(SECTOR * size * sizeof(char)); 127 int status; 128 129 if (write_sectors(drive_info, lba, data, size) == -1) 130 return -1; /* Write failure */ 131 132 if (read_sectors(drive_info, rb, lba, size) == -1) 133 return -1; /* Readback failure */ 134 135 status = memcmp(data, rb, SECTOR * size); 136 free(rb); 137 return status ? -1 : 0; 138 } 139
