aboutsummaryrefslogtreecommitdiffstats
path: root/com32/lib/syslinux/disk.c
diff options
context:
space:
mode:
Diffstat (limited to 'com32/lib/syslinux/disk.c')
-rw-r--r--com32/lib/syslinux/disk.c507
1 files changed, 507 insertions, 0 deletions
diff --git a/com32/lib/syslinux/disk.c b/com32/lib/syslinux/disk.c
new file mode 100644
index 00000000..678e4bd2
--- /dev/null
+++ b/com32/lib/syslinux/disk.c
@@ -0,0 +1,507 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * Copyright 2003-2009 H. Peter Anvin - All Rights Reserved
+ * Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
+ * Copyright (C) 2010 Shao Miller
+ *
+ * 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.
+ *
+ * ----------------------------------------------------------------------- */
+
+/**
+ * @file disk.c
+ *
+ * Deal with disks and partitions
+ */
+
+#include <dprintf.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslinux/disk.h>
+
+/**
+ * Call int 13h, but with retry on failure. Especially floppies need this.
+ *
+ * @v inreg CPU register settings upon INT call
+ * @v outreg CPU register settings returned by INT call
+ * @ret (int) 0 upon success, -1 upon failure
+ */
+int disk_int13_retry(const com32sys_t * inreg, com32sys_t * outreg)
+{
+ int retry = 6; /* Number of retries */
+ com32sys_t tmpregs;
+
+ if (!outreg)
+ outreg = &tmpregs;
+
+ while (retry--) {
+ __intcall(0x13, inreg, outreg);
+ if (!(outreg->eflags.l & EFLAGS_CF))
+ return 0; /* CF=0, OK */
+ }
+
+ return -1; /* Error */
+}
+
+/**
+ * Query disk parameters and EBIOS availability for a particular disk.
+ *
+ * @v disk The INT 0x13 disk drive number to process
+ * @v diskinfo The structure to save the queried params to
+ * @ret (int) 0 upon success, -1 upon failure
+ */
+int disk_get_params(int disk, struct disk_info *const diskinfo)
+{
+ static com32sys_t getparm, parm, getebios, ebios;
+
+ diskinfo->disk = disk;
+ diskinfo->ebios = diskinfo->cbios = 0;
+
+ /* Get EBIOS support */
+ getebios.eax.w[0] = 0x4100;
+ getebios.ebx.w[0] = 0x55aa;
+ getebios.edx.b[0] = disk;
+ getebios.eflags.b[0] = 0x3; /* CF set */
+
+ __intcall(0x13, &getebios, &ebios);
+
+ if (!(ebios.eflags.l & EFLAGS_CF) &&
+ ebios.ebx.w[0] == 0xaa55 && (ebios.ecx.b[0] & 1)) {
+ diskinfo->ebios = 1;
+ }
+
+ /* Get disk parameters -- really only useful for
+ hard disks, but if we have a partitioned floppy
+ it's actually our best chance... */
+ getparm.eax.b[1] = 0x08;
+ getparm.edx.b[0] = disk;
+
+ __intcall(0x13, &getparm, &parm);
+
+ if (parm.eflags.l & EFLAGS_CF)
+ return diskinfo->ebios ? 0 : -1;
+
+ diskinfo->head = parm.edx.b[1] + 1;
+ diskinfo->sect = parm.ecx.b[0] & 0x3f;
+ if (diskinfo->sect == 0) {
+ diskinfo->sect = 1;
+ } else {
+ diskinfo->cbios = 1; /* Valid geometry */
+ }
+
+ return 0;
+}
+
+/**
+ * Get disk block(s) and return a malloc'd buffer.
+ *
+ * @v diskinfo The disk drive to read from
+ * @v lba The logical block address to begin reading at
+ * @v count The number of sectors to read
+ * @ret data An allocated buffer with the read data
+ *
+ * Uses the disk number and information from diskinfo. Read count sectors
+ * from drive, starting at lba. Return a new buffer, or NULL upon failure.
+ */
+void *disk_read_sectors(const struct disk_info *const diskinfo, uint64_t lba,
+ uint8_t count)
+{
+ com32sys_t inreg;
+ struct disk_ebios_dapa *dapa = __com32.cs_bounce;
+ void *buf = (char *)__com32.cs_bounce + SECTOR;
+ void *data;
+
+ if (!count)
+ /* Silly */
+ return NULL;
+
+ memset(&inreg, 0, sizeof inreg);
+
+ if (diskinfo->ebios) {
+ dapa->len = sizeof(*dapa);
+ dapa->count = count;
+ dapa->off = OFFS(buf);
+ dapa->seg = SEG(buf);
+ dapa->lba = lba;
+
+ inreg.esi.w[0] = OFFS(dapa);
+ inreg.ds = SEG(dapa);
+ inreg.edx.b[0] = diskinfo->disk;
+ inreg.eax.b[1] = 0x42; /* Extended read */
+ } else {
+ unsigned int c, h, s, t;
+
+ if (!diskinfo->cbios) {
+ /* We failed to get the geometry */
+
+ if (lba)
+ return NULL; /* Can only read MBR */
+
+ s = 1;
+ h = 0;
+ c = 0;
+ } else {
+ s = (lba % diskinfo->sect) + 1;
+ t = lba / diskinfo->sect; /* Track = head*cyl */
+ h = t % diskinfo->head;
+ c = t / diskinfo->head;
+ }
+
+ if (s > 63 || h > 256 || c > 1023)
+ return NULL;
+
+ inreg.eax.b[0] = count;
+ inreg.eax.b[1] = 0x02; /* Read */
+ inreg.ecx.b[1] = c & 0xff;
+ inreg.ecx.b[0] = s + (c >> 6);
+ inreg.edx.b[1] = h;
+ inreg.edx.b[0] = diskinfo->disk;
+ inreg.ebx.w[0] = OFFS(buf);
+ inreg.es = SEG(buf);
+ }
+
+ if (disk_int13_retry(&inreg, NULL))
+ return NULL;
+
+ data = malloc(count * SECTOR);
+ if (data)
+ memcpy(data, buf, count * SECTOR);
+ return data;
+}
+
+/**
+ * Write a disk block.
+ *
+ * @v diskinfo The disk drive to write to
+ * @v lba The logical block address to begin writing at
+ * @v data The data to write
+ * @ret (int) 0 upon success, -1 upon failure
+ *
+ * Uses the disk number and information from diskinfo.
+ * Write a sector to a disk drive, starting at lba.
+ */
+int disk_write_sector(const struct disk_info *const diskinfo, unsigned int lba,
+ const void *data)
+{
+ com32sys_t inreg;
+ struct disk_ebios_dapa *dapa = __com32.cs_bounce;
+ void *buf = (char *)__com32.cs_bounce + SECTOR;
+
+ memcpy(buf, data, SECTOR);
+ memset(&inreg, 0, sizeof inreg);
+
+ if (diskinfo->ebios) {
+ dapa->len = sizeof(*dapa);
+ dapa->count = 1; /* 1 sector */
+ dapa->off = OFFS(buf);
+ dapa->seg = SEG(buf);
+ dapa->lba = lba;
+
+ inreg.esi.w[0] = OFFS(dapa);
+ inreg.ds = SEG(dapa);
+ inreg.edx.b[0] = diskinfo->disk;
+ inreg.eax.w[0] = 0x4300; /* Extended write */
+ } else {
+ unsigned int c, h, s, t;
+
+ if (!diskinfo->cbios) {
+ /* We failed to get the geometry */
+
+ if (lba)
+ return -1; /* Can only write MBR */
+
+ s = 1;
+ h = 0;
+ c = 0;
+ } else {
+ s = (lba % diskinfo->sect) + 1;
+ t = lba / diskinfo->sect; /* Track = head*cyl */
+ h = t % diskinfo->head;
+ c = t / diskinfo->head;
+ }
+
+ if (s > 63 || h > 256 || c > 1023)
+ return -1;
+
+ inreg.eax.w[0] = 0x0301; /* Write one sector */
+ inreg.ecx.b[1] = c & 0xff;
+ inreg.ecx.b[0] = s + (c >> 6);
+ inreg.edx.b[1] = h;
+ inreg.edx.b[0] = diskinfo->disk;
+ inreg.ebx.w[0] = OFFS(buf);
+ inreg.es = SEG(buf);
+ }
+
+ if (disk_int13_retry(&inreg, NULL))
+ return -1;
+
+ return 0; /* ok */
+}
+
+/**
+ * Write a disk block and verify it was written.
+ *
+ * @v diskinfo The disk drive to write to
+ * @v lba The logical block address to begin writing at
+ * @v buf The data to write
+ * @ret rv 0 upon success, -1 upon failure
+ *
+ * Uses the disk number and information from diskinfo.
+ * Writes a sector to a disk drive starting at lba, then reads it back
+ * to verify it was written correctly.
+ */
+int disk_write_verify_sector(const struct disk_info *const diskinfo,
+ unsigned int lba, const void *buf)
+{
+ char *rb;
+ int rv;
+
+ rv = disk_write_sector(diskinfo, lba, buf);
+ if (rv)
+ return rv; /* Write failure */
+ rb = disk_read_sectors(diskinfo, lba, 1);
+ if (!rb)
+ return -1; /* Readback failure */
+ rv = memcmp(buf, rb, SECTOR);
+ free(rb);
+ return rv ? -1 : 0;
+}
+
+/**
+ * Dump info about a DOS partition entry
+ *
+ * @v part The 16-byte partition entry to examine
+ */
+void disk_dos_part_dump(const struct disk_dos_part_entry *const part)
+{
+ (void)part;
+ dprintf("Partition status _____ : 0x%.2x\n"
+ "Partition CHS start\n"
+ " Cylinder ___________ : 0x%.4x (%u)\n"
+ " Head _______________ : 0x%.2x (%u)\n"
+ " Sector _____________ : 0x%.2x (%u)\n"
+ "Partition type _______ : 0x%.2x\n"
+ "Partition CHS end\n"
+ " Cylinder ___________ : 0x%.4x (%u)\n"
+ " Head _______________ : 0x%.2x (%u)\n"
+ " Sector _____________ : 0x%.2x (%u)\n"
+ "Partition LBA start __ : 0x%.8x (%u)\n"
+ "Partition LBA count __ : 0x%.8x (%u)\n"
+ "-------------------------------\n",
+ part->active_flag,
+ chs_cylinder(part->start),
+ chs_cylinder(part->start),
+ chs_head(part->start),
+ chs_head(part->start),
+ chs_sector(part->start),
+ chs_sector(part->start),
+ part->ostype,
+ chs_cylinder(part->end),
+ chs_cylinder(part->end),
+ chs_head(part->end),
+ chs_head(part->end),
+ chs_sector(part->end),
+ chs_sector(part->end),
+ part->start_lba, part->start_lba, part->length, part->length);
+}
+
+/* Trivial error message output */
+static inline void error(const char *msg)
+{
+ fputs(msg, stderr);
+}
+
+/**
+ * This walk-map effectively reverses the little-endian
+ * portions of a GPT disk/partition GUID for a string representation.
+ * There might be a better header for this...
+ */
+static const char guid_le_walk_map[] = {
+ 3, -1, -1, -1, 0,
+ 5, -1, 0,
+ 3, -1, 0,
+ 2, 1, 0,
+ 1, 1, 1, 1, 1, 1
+};
+
+/**
+ * Fill a buffer with a textual GUID representation.
+ *
+ * @v buf Points to a minimum array of 37 chars
+ * @v id The GUID to represent as text
+ *
+ * The buffer must be >= char[37] and will be populated
+ * with an ASCII NUL C string terminator.
+ * Example: 11111111-2222-3333-4444-444444444444
+ * Endian: LLLLLLLL-LLLL-LLLL-BBBB-BBBBBBBBBBBB
+ */
+void guid_to_str(char *buf, const struct guid *const id)
+{
+ unsigned int i = 0;
+ const char *walker = (const char *)id;
+
+ while (i < sizeof(guid_le_walk_map)) {
+ walker += guid_le_walk_map[i];
+ if (!guid_le_walk_map[i])
+ *buf = '-';
+ else {
+ *buf = ((*walker & 0xF0) >> 4) + '0';
+ if (*buf > '9')
+ *buf += 'A' - '9' - 1;
+ buf++;
+ *buf = (*walker & 0x0F) + '0';
+ if (*buf > '9')
+ *buf += 'A' - '9' - 1;
+ }
+ buf++;
+ i++;
+ }
+ *buf = 0;
+}
+
+/**
+ * Create a GUID structure from a textual GUID representation.
+ *
+ * @v buf Points to a GUID string to parse
+ * @v id Points to a GUID to be populated
+ * @ret (int) Returns 0 upon success, -1 upon failure
+ *
+ * The input buffer must be >= 32 hexadecimal chars and be
+ * terminated with an ASCII NUL. Returns non-zero on failure.
+ * Example: 11111111-2222-3333-4444-444444444444
+ * Endian: LLLLLLLL-LLLL-LLLL-BBBB-BBBBBBBBBBBB
+ */
+int str_to_guid(const char *buf, struct guid *const id)
+{
+ char guid_seq[sizeof(struct guid) * 2];
+ unsigned int i = 0;
+ char *walker = (char *)id;
+
+ while (*buf && i < sizeof(guid_seq)) {
+ switch (*buf) {
+ /* Skip these three characters */
+ case '{':
+ case '}':
+ case '-':
+ break;
+ default:
+ /* Copy something useful to the temp. sequence */
+ if ((*buf >= '0') && (*buf <= '9'))
+ guid_seq[i] = *buf - '0';
+ else if ((*buf >= 'A') && (*buf <= 'F'))
+ guid_seq[i] = *buf - 'A' + 10;
+ else if ((*buf >= 'a') && (*buf <= 'f'))
+ guid_seq[i] = *buf - 'a' + 10;
+ else {
+ /* Or not */
+ error("Illegal character in GUID!\n");
+ return -1;
+ }
+ i++;
+ }
+ buf++;
+ }
+ /* Check for insufficient valid characters */
+ if (i < sizeof(guid_seq)) {
+ error("Too few GUID characters!\n");
+ return -1;
+ }
+ buf = guid_seq;
+ i = 0;
+ while (i < sizeof(guid_le_walk_map)) {
+ if (!guid_le_walk_map[i])
+ i++;
+ walker += guid_le_walk_map[i];
+ *walker = *buf << 4;
+ buf++;
+ *walker |= *buf;
+ buf++;
+ i++;
+ }
+ return 0;
+}
+
+/**
+ * Display GPT partition details.
+ *
+ * @v gpt_part The GPT partition entry to display
+ */
+void disk_gpt_part_dump(const struct disk_gpt_part_entry *const gpt_part)
+{
+ unsigned int i;
+ char guid_text[37];
+
+ dprintf("----------------------------------\n"
+ "GPT part. LBA first __ : 0x%.16llx\n"
+ "GPT part. LBA last ___ : 0x%.16llx\n"
+ "GPT part. attribs ____ : 0x%.16llx\n"
+ "GPT part. name _______ : '",
+ gpt_part->lba_first, gpt_part->lba_last, gpt_part->attribs);
+ for (i = 0; i < sizeof(gpt_part->name); i++) {
+ if (gpt_part->name[i])
+ dprintf("%c", gpt_part->name[i]);
+ }
+ dprintf("'");
+ guid_to_str(guid_text, &gpt_part->type);
+ dprintf("GPT part. type GUID __ : {%s}\n", guid_text);
+ guid_to_str(guid_text, &gpt_part->uid);
+ dprintf("GPT part. unique ID __ : {%s}\n", guid_text);
+}
+
+/**
+ * Display GPT header details.
+ *
+ * @v gpt The GPT header to display
+ */
+void disk_gpt_header_dump(const struct disk_gpt_header *const gpt)
+{
+ char guid_text[37];
+
+ printf("GPT sig ______________ : '%8.8s'\n"
+ "GPT major revision ___ : 0x%.4x\n"
+ "GPT minor revision ___ : 0x%.4x\n"
+ "GPT header size ______ : 0x%.8x\n"
+ "GPT header checksum __ : 0x%.8x\n"
+ "GPT reserved _________ : '%4.4s'\n"
+ "GPT LBA current ______ : 0x%.16llx\n"
+ "GPT LBA alternative __ : 0x%.16llx\n"
+ "GPT LBA first usable _ : 0x%.16llx\n"
+ "GPT LBA last usable __ : 0x%.16llx\n"
+ "GPT LBA part. table __ : 0x%.16llx\n"
+ "GPT partition count __ : 0x%.8x\n"
+ "GPT partition size ___ : 0x%.8x\n"
+ "GPT part. table chksum : 0x%.8x\n",
+ gpt->sig,
+ gpt->rev.fields.major,
+ gpt->rev.fields.minor,
+ gpt->hdr_size,
+ gpt->chksum,
+ gpt->reserved1,
+ gpt->lba_cur,
+ gpt->lba_alt,
+ gpt->lba_first_usable,
+ gpt->lba_last_usable,
+ gpt->lba_table, gpt->part_count, gpt->part_size, gpt->table_chksum);
+ guid_to_str(guid_text, &gpt->disk_guid);
+ printf("GPT disk GUID ________ : {%s}\n", guid_text);
+}