--- /dev/null
+#include "devices/partition.h"
+#include <packed.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include "devices/block.h"
+#include "threads/malloc.h"
+
+/* A partition of a block device. */
+struct partition
+ {
+ struct block *block; /* Underlying block device. */
+ block_sector_t start; /* First sector within device. */
+ };
+
+static struct block_operations partition_operations;
+
+static void read_partition_table (struct block *, block_sector_t sector,
+ block_sector_t primary_extended_sector,
+ int *part_nr);
+static void found_partition (struct block *, uint8_t type,
+ block_sector_t start, block_sector_t size,
+ int part_nr);
+static const char *partition_type_name (uint8_t);
+
+/* Scans BLOCK for partitions of interest to Pintos. */
+void
+partition_scan (struct block *block)
+{
+ int part_nr = 0;
+ read_partition_table (block, 0, 0, &part_nr);
+ if (part_nr == 0)
+ printf ("%s: Device contains no partitions\n", block_name (block));
+}
+
+/* Reads the partition table in the given SECTOR of BLOCK and
+ scans it for partitions of interest to Pintos.
+
+ If SECTOR is 0, so that this is the top-level partition table
+ on BLOCK, then PRIMARY_EXTENDED_SECTOR is not meaningful;
+ otherwise, it should designate the sector of the top-level
+ extended partition table that was traversed to arrive at
+ SECTOR, for use in finding logical partitions (see the large
+ comment below).
+
+ PART_NR points to the number of non-empty primary or logical
+ partitions already encountered on BLOCK. It is incremented as
+ partitions are found. */
+static void
+read_partition_table (struct block *block, block_sector_t sector,
+ block_sector_t primary_extended_sector,
+ int *part_nr)
+{
+ /* Format of a partition table entry. See [Partitions]. */
+ struct partition_table_entry
+ {
+ uint8_t bootable; /* 0x00=not bootable, 0x80=bootable. */
+ uint8_t start_chs[3]; /* Encoded starting cylinder, head, sector. */
+ uint8_t type; /* Partition type (see partition_type_name). */
+ uint8_t end_chs[3]; /* Encoded ending cylinder, head, sector. */
+ uint32_t offset; /* Start sector offset from partition table. */
+ uint32_t size; /* Number of sectors. */
+ }
+ PACKED;
+
+ /* Partition table sector. */
+ struct partition_table
+ {
+ uint8_t loader[446]; /* Loader, in top-level partition table. */
+ struct partition_table_entry partitions[4]; /* Table entries. */
+ uint16_t signature; /* Should be 0xaa55. */
+ }
+ PACKED;
+
+ struct partition_table *pt;
+ size_t i;
+
+ /* Check SECTOR validity. */
+ if (sector >= block_size (block))
+ {
+ printf ("%s: Partition table at sector %"PRDSNu" past end of device.\n",
+ block_name (block), sector);
+ return;
+ }
+
+ /* Read sector. */
+ ASSERT (sizeof *pt == BLOCK_SECTOR_SIZE);
+ pt = malloc (sizeof *pt);
+ if (pt == NULL)
+ PANIC ("Failed to allocate memory for partition table.");
+ block_read (block, 0, pt);
+
+ /* Check signature. */
+ if (pt->signature != 0xaa55)
+ {
+ if (primary_extended_sector == 0)
+ printf ("%s: Invalid partition table signature\n", block_name (block));
+ else
+ printf ("%s: Invalid extended partition table in sector %"PRDSNu"\n",
+ block_name (block), sector);
+ free (pt);
+ return;
+ }
+
+ /* Parse partitions. */
+ for (i = 0; i < sizeof pt->partitions / sizeof *pt->partitions; i++)
+ {
+ struct partition_table_entry *e = &pt->partitions[i];
+
+ if (e->size == 0 || e->type == 0)
+ {
+ /* Ignore empty partition. */
+ }
+ else if (e->type == 0x05 /* Extended partition. */
+ || e->type == 0x0f /* Windows 98 extended partition. */
+ || e->type == 0x85 /* Linux extended partition. */
+ || e->type == 0xc5) /* DR-DOS extended partition. */
+ {
+ printf ("%s: Extended partition in sector %"PRDSNu"\n",
+ block_name (block), sector);
+
+ /* The interpretation of the offset field for extended
+ partitions is bizarre. When the extended partition
+ table entry is in the master boot record, that is,
+ the device's primary partition table in sector 0, then
+ the offset is an absolute sector number. Otherwise,
+ no matter how deep the partition table we're reading
+ is nested, the offset is relative to the start of
+ the extended partition that the MBR points to. */
+ if (sector == 0)
+ read_partition_table (block, e->offset, e->offset, part_nr);
+ else
+ read_partition_table (block, e->offset + primary_extended_sector,
+ primary_extended_sector, part_nr);
+ }
+ else
+ {
+ ++*part_nr;
+
+ found_partition (block, e->type, e->offset + sector,
+ e->size, *part_nr);
+ }
+ }
+
+ free (pt);
+}
+
+/* We have found a primary or logical partition of the given TYPE
+ on BLOCK, starting at sector START and continuing for SIZE
+ sectors, which we are giving the partition number PART_NR.
+ Check whether this is a partition of interest to Pintos, and
+ if so then add it to the proper element of partitions[]. */
+static void
+found_partition (struct block *block, uint8_t part_type,
+ block_sector_t start, block_sector_t size,
+ int part_nr)
+{
+ if (start >= block_size (block))
+ printf ("%s%d: Partition starts past end of device (sector %"PRDSNu")\n",
+ block_name (block), part_nr, start);
+ else if (start + size < start || start + size > block_size (block))
+ printf ("%s%d: Partition end (%"PRDSNu") past end of device (%"PRDSNu")\n",
+ block_name (block), part_nr, start + size, block_size (block));
+ else
+ {
+ enum block_type type = (part_type == 0x20 ? BLOCK_KERNEL
+ : part_type == 0x21 ? BLOCK_FILESYS
+ : part_type == 0x22 ? BLOCK_SCRATCH
+ : part_type == 0x23 ? BLOCK_SWAP
+ : BLOCK_FOREIGN);
+ struct partition *p;
+ char extra_info[128];
+ char name[16];
+
+ p = malloc (sizeof *p);
+ if (p == NULL)
+ PANIC ("Failed to allocate memory for partition descriptor");
+ p->block = block;
+ p->start = start;
+
+ snprintf (name, sizeof name, "%s%d", block_name (block), part_nr);
+ snprintf (extra_info, sizeof extra_info, "%s (%02x)",
+ partition_type_name (part_type), part_type);
+ block_register (name, type, extra_info, size, &partition_operations, p);
+ }
+}
+
+/* Returns a human-readable name for the given partition TYPE. */
+static const char *
+partition_type_name (uint8_t type)
+{
+ /* Name of each known type of partition.
+ From util-linux-2.12r/fdisk/i386_sys_types.c.
+ This initializer makes use of a C99 feature that allows
+ array elements to be initialized by index. */
+ static const char *type_names[256] =
+ {
+ [0x00] = "Empty",
+ [0x01] = "FAT12",
+ [0x02] = "XENIX root",
+ [0x03] = "XENIX usr",
+ [0x04] = "FAT16 <32M",
+ [0x05] = "Extended",
+ [0x06] = "FAT16",
+ [0x07] = "HPFS/NTFS",
+ [0x08] = "AIX",
+ [0x09] = "AIX bootable",
+ [0x0a] = "OS/2 Boot Manager",
+ [0x0b] = "W95 FAT32",
+ [0x0c] = "W95 FAT32 (LBA)",
+ [0x0e] = "W95 FAT16 (LBA)",
+ [0x0f] = "W95 Ext'd (LBA)",
+ [0x10] = "OPUS",
+ [0x11] = "Hidden FAT12",
+ [0x12] = "Compaq diagnostics",
+ [0x14] = "Hidden FAT16 <32M",
+ [0x16] = "Hidden FAT16",
+ [0x17] = "Hidden HPFS/NTFS",
+ [0x18] = "AST SmartSleep",
+ [0x1b] = "Hidden W95 FAT32",
+ [0x1c] = "Hidden W95 FAT32 (LBA)",
+ [0x1e] = "Hidden W95 FAT16 (LBA)",
+ [0x20] = "Pintos OS kernel",
+ [0x21] = "Pintos file system",
+ [0x22] = "Pintos scratch",
+ [0x23] = "Pintos swap",
+ [0x24] = "NEC DOS",
+ [0x39] = "Plan 9",
+ [0x3c] = "PartitionMagic recovery",
+ [0x40] = "Venix 80286",
+ [0x41] = "PPC PReP Boot",
+ [0x42] = "SFS",
+ [0x4d] = "QNX4.x",
+ [0x4e] = "QNX4.x 2nd part",
+ [0x4f] = "QNX4.x 3rd part",
+ [0x50] = "OnTrack DM",
+ [0x51] = "OnTrack DM6 Aux1",
+ [0x52] = "CP/M",
+ [0x53] = "OnTrack DM6 Aux3",
+ [0x54] = "OnTrackDM6",
+ [0x55] = "EZ-Drive",
+ [0x56] = "Golden Bow",
+ [0x5c] = "Priam Edisk",
+ [0x61] = "SpeedStor",
+ [0x63] = "GNU HURD or SysV",
+ [0x64] = "Novell Netware 286",
+ [0x65] = "Novell Netware 386",
+ [0x70] = "DiskSecure Multi-Boot",
+ [0x75] = "PC/IX",
+ [0x80] = "Old Minix",
+ [0x81] = "Minix / old Linux",
+ [0x82] = "Linux swap / Solaris",
+ [0x83] = "Linux",
+ [0x84] = "OS/2 hidden C: drive",
+ [0x85] = "Linux extended",
+ [0x86] = "NTFS volume set",
+ [0x87] = "NTFS volume set",
+ [0x88] = "Linux plaintext",
+ [0x8e] = "Linux LVM",
+ [0x93] = "Amoeba",
+ [0x94] = "Amoeba BBT",
+ [0x9f] = "BSD/OS",
+ [0xa0] = "IBM Thinkpad hibernation",
+ [0xa5] = "FreeBSD",
+ [0xa6] = "OpenBSD",
+ [0xa7] = "NeXTSTEP",
+ [0xa8] = "Darwin UFS",
+ [0xa9] = "NetBSD",
+ [0xab] = "Darwin boot",
+ [0xb7] = "BSDI fs",
+ [0xb8] = "BSDI swap",
+ [0xbb] = "Boot Wizard hidden",
+ [0xbe] = "Solaris boot",
+ [0xbf] = "Solaris",
+ [0xc1] = "DRDOS/sec (FAT-12)",
+ [0xc4] = "DRDOS/sec (FAT-16 < 32M)",
+ [0xc6] = "DRDOS/sec (FAT-16)",
+ [0xc7] = "Syrinx",
+ [0xda] = "Non-FS data",
+ [0xdb] = "CP/M / CTOS / ...",
+ [0xde] = "Dell Utility",
+ [0xdf] = "BootIt",
+ [0xe1] = "DOS access",
+ [0xe3] = "DOS R/O",
+ [0xe4] = "SpeedStor",
+ [0xeb] = "BeOS fs",
+ [0xee] = "EFI GPT",
+ [0xef] = "EFI (FAT-12/16/32)",
+ [0xf0] = "Linux/PA-RISC boot",
+ [0xf1] = "SpeedStor",
+ [0xf4] = "SpeedStor",
+ [0xf2] = "DOS secondary",
+ [0xfd] = "Linux raid autodetect",
+ [0xfe] = "LANstep",
+ [0xff] = "BBT",
+ };
+
+ return type_names[type] != NULL ? type_names[type] : "Unknown";
+}
+
+/* Reads sector SECTOR from partition P into BUFFER, which must
+ have room for BLOCK_SECTOR_SIZE bytes. */
+static void
+partition_read (void *p_, block_sector_t sector, void *buffer)
+{
+ struct partition *p = p_;
+ block_read (p->block, p->start + sector, buffer);
+}
+
+/* Write sector SECTOR to partition P from BUFFER, which must
+ contain BLOCK_SECTOR_SIZE bytes. Returns after the block has
+ acknowledged receiving the data. */
+static void
+partition_write (void *p_, block_sector_t sector, const void *buffer)
+{
+ struct partition *p = p_;
+ block_write (p->block, p->start + sector, buffer);
+}
+
+static struct block_operations partition_operations =
+ {
+ partition_read,
+ partition_write
+ };
projects / pintos-anon / blobdiff