Changeset 440b0ce in mainline

Timestamp:

2009-09-01T20:34:33Z (15 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

e27b89a

Parents:

822d22a

Message:

Add support for logical partitions.

File:

• uspace/srv/part/mbr_part/mbr_part.c (modified) (10 diffs)

uspace/srv/part/mbr_part/mbr_part.c

@@ -38 +38 @@
  * and provides one for each partition.
  *
+ * Limitations:
+ *
  * Only works with boot records using LBA. CHS-only records are not
- * supported. Only primary partition records are supported.
+ * supported. Maximum number of partitions is fixed.
  */
 
@@ -67 +69 @@
 
         /** Boot record signature */
-        BR_SIGNATURE    = 0xAA55
+        BR_SIGNATURE    = 0xAA55,
+
+        /** Maximum number of partitions */
+        MAX_PART        = 64
+};
+
+enum ptype {
+        /** Extended partition */
+        PT_EXTENDED     = 0x05
 };
 
@@ -87 +97 @@
         /** CHS of fist block in partition */
         uint8_t first_chs[3];
+        /** Partition type */
+        uint8_t ptype;
         /** CHS of last block in partition */
         uint8_t last_chs[3];
-        /** Partition type */
-        uint8_t ptype;
         /** LBA of first block in partition */
         uint32_t first_lba;
@@ -120 +130 @@
 static dev_handle_t indev_handle;
 
-static part_t primary[N_PRIMARY];
+static part_t primary[MAX_PART];
 
 static int mbr_init(const char *dev_name);
 static int mbr_part_read(void);
+static void mbr_pte_to_part(uint32_t base, const pt_entry_t *pte, part_t *part);
 static void mbr_connection(ipc_callid_t iid, ipc_call_t *icall);
 static int mbr_bd_read(part_t *p, uint64_t ba, size_t cnt, void *buf);
@@ -129 +140 @@
 static int mbr_bsa_translate(part_t *p, uint64_t ba, size_t cnt, uint64_t *gba);
 
+/** Total number of partitions entries in @c primary (including non-present). */
+static int total_part;
 
 int main(int argc, char **argv)
@@ -196 +209 @@
 
         /* Create partition devices. */
-        for (i = 0; i < N_PRIMARY; ++i) {
+        for (i = 0; i < total_part; ++i) {
                 /* Skip absent partitions. */
                 if (!primary[i].present)
@@ -228 +241 @@
 {
         int i, rc;
-        br_block_t *mbr;
+        br_block_t *brb;
         uint16_t sgn;
-        uint32_t sa, len;
-
-        rc = block_bb_read(indev_handle, 0);
+        uint32_t ba;
+        part_t *ext_part, cp;
+        uint32_t base;
+
+        brb = malloc(sizeof(br_block_t));
+        if (brb == NULL) {
+                printf(NAME ": Failed allocating memory.\n");
+                return ENOMEM;  
+        }
+
+        /*
+         * Read primary partition entries.
+         */
+
+        rc = block_read_direct(indev_handle, 0, 1, brb);
         if (rc != EOK) {
                 printf(NAME ": Failed reading MBR block.\n");
@@ -238 +263 @@
         }
 
-        mbr = block_bb_get(indev_handle);
-        sgn = uint16_t_le2host(mbr->signature);
-
+        sgn = uint16_t_le2host(brb->signature);
         if (sgn != BR_SIGNATURE) {
                 printf(NAME ": Invalid boot record signature 0x%04X.\n", sgn);
@@ -246 +269 @@
         }
 
+        ext_part = NULL;
+
         for (i = 0; i < N_PRIMARY; ++i) {
-                sa  = uint32_t_le2host(mbr->pte[i].first_lba);
-                len = uint32_t_le2host(mbr->pte[i].length);
-
-                primary[i].start_addr = sa;
-                primary[i].length = len;
-
-                primary[i].present = (sa != 0 || len != 0) ? true : false;
-                primary[i].dev = 0;
-        }
+                mbr_pte_to_part(0, &brb->pte[i], &primary[i]);
+
+                if (brb->pte[i].ptype == PT_EXTENDED) {
+                        primary[i].present = false;
+                        ext_part = &primary[i];
+                }
+        }
+
+        if (ext_part == NULL)
+                return EOK;
+
+        printf("Extended partition found.\n");
+
+        /*
+         * Read extended partition entries.
+         */
+
+        cp.start_addr = ext_part->start_addr;
+        cp.length = ext_part->length;
+        base = ext_part->start_addr;
+
+        do {
+                /*
+                 * Addressing in the EBR chain is relative to the beginning
+                 * of the extended partition.
+                 */
+                ba = cp.start_addr;
+                rc = block_read_direct(indev_handle, ba, 1, brb);
+                if (rc != EOK) {
+                        printf(NAME ": Failed reading EBR block at %u.\n", ba);
+                        return rc;
+                }
+
+                sgn = uint16_t_le2host(brb->signature);
+                if (sgn != BR_SIGNATURE) {
+                        printf(NAME ": Invalid boot record signature 0x%04X "
+                            " in EBR at %u.\n", sgn, ba);
+                        return EINVAL;
+                }
+
+                /* First PTE is the logical partition itself. */
+                mbr_pte_to_part(base, &brb->pte[0], &primary[i]);
+                ++i;
+
+                /* Second PTE describes next chain element. */
+                mbr_pte_to_part(base, &brb->pte[1], &cp);
+        } while (cp.present && i < MAX_PART);
+
+        total_part = i;
 
         return EOK;
+}
+
+/** Parse partition table entry. */
+static void mbr_pte_to_part(uint32_t base, const pt_entry_t *pte, part_t *part)
+{
+        uint32_t sa, len;
+
+        sa = uint32_t_le2host(pte->first_lba);
+        len = uint32_t_le2host(pte->length);
+
+        part->start_addr = base + sa;
+        part->length     = len;
+
+        part->present = (sa != 0 || len != 0) ? true : false;
+        part->dev = 0;
 }
 
@@ -280 +360 @@
         /* Determine which partition device is the client connecting to. */
         pidx = -1;
-        for (i = 0; i < N_PRIMARY; i++)
+        for (i = 0; i < total_part; i++)
                 if (primary[i].dev == dh)
                         pidx = i;