[lib][partition] add simple block device partition scanner (MBR only)
diff --git a/include/lib/partition.h b/include/lib/partition.h
new file mode 100644
index 0000000..576bc97
--- /dev/null
+++ b/include/lib/partition.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2009 Travis Geiselbrecht
+ *
+ * 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.
+ */
+#ifndef __LIB_PARTITION_H
+#define __LIB_PARTITION_H
+
+#include <sys/types.h>
+
+/* examine and try to publish partitions on a particular device at a particular offset */
+int partition_publish(const char *device, off_t offset);
+
+/* remove any published subdevices on this device */
+int partition_unpublish(const char *device);
+
+#endif
+
diff --git a/lib/partition/partition.c b/lib/partition/partition.c
new file mode 100644
index 0000000..5565fe5
--- /dev/null
+++ b/lib/partition/partition.c
@@ -0,0 +1,153 @@
+/*
+ * Copyright (c) 2009 Travis Geiselbrecht
+ *
+ * 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 <debug.h>
+#include <printf.h>
+#include <string.h>
+#include <compiler.h>
+#include <stdlib.h>
+#include <arch.h>
+#include <lib/bio.h>
+#include <lib/partition.h>
+
+struct chs {
+ uint8_t c;
+ uint8_t h;
+ uint8_t s;
+} __PACKED;
+
+struct mbr_part {
+ uint8_t status;
+ struct chs start;
+ uint8_t type;
+ struct chs end;
+ uint32_t lba_start;
+ uint32_t lba_length;
+} __PACKED;
+
+static status_t validate_mbr_partition(bdev_t *dev, const struct mbr_part *part)
+{
+ /* check for invalid types */
+ if (part->type == 0)
+ return -1;
+ /* check for invalid status */
+ if (part->status != 0x80 && part->status != 0x00)
+ return -1;
+
+ /* make sure the range fits within the device */
+ if (part->lba_start >= dev->block_count)
+ return -1;
+ if ((part->lba_start + part->lba_length) > dev->block_count)
+ return -1;
+
+ /* that's about all we can do, MBR has no other good way to see if it's valid */
+
+ return 0;
+}
+
+int partition_publish(const char *device, off_t offset)
+{
+ int err = 0;
+ int count = 0;
+
+ // clear any partitions that may have already existed
+ partition_unpublish(device);
+
+ bdev_t *dev = bio_open(device);
+ if (!dev) {
+ printf("partition_publish: unable to open device\n");
+ return -1;
+ }
+
+ // get a dma aligned and padded block to read info
+ STACKBUF_DMA_ALIGN(buf, dev->block_size);
+
+ /* sniff for MBR partition types */
+ do {
+ int i;
+
+ err = bio_read(dev, buf, offset, 512);
+ if (err < 0)
+ goto err;
+
+ /* look for the aa55 tag */
+ if (buf[510] != 0x55 || buf[511] != 0xaa)
+ break;
+
+ /* see if a partition table makes sense here */
+ struct mbr_part part[4];
+ memcpy(part, buf + 446, sizeof(part));
+
+#if DEBUGLEVEL >= INFO
+ dprintf(INFO, "mbr partition table dump:\n");
+ for (i=0; i < 4; i++) {
+ dprintf(INFO, "\t%i: status 0x%hhx, type 0x%hhx, start 0x%x, len 0x%x\n", i, part[i].status, part[i].type, part[i].lba_start, part[i].lba_length);
+ }
+#endif
+
+ /* validate each of the partition entries */
+ for (i=0; i < 4; i++) {
+ if (validate_mbr_partition(dev, &part[i]) >= 0) {
+ // publish it
+ char subdevice[128];
+
+ sprintf(subdevice, "%sp%d", device, i);
+
+ err = bio_publish_subdevice(device, subdevice, part[i].lba_start, part[i].lba_length);
+ if (err < 0) {
+ dprintf(INFO, "error publishing subdevice '%s'\n", subdevice);
+ continue;
+ }
+ count++;
+ }
+ }
+ } while(0);
+
+ bio_close(dev);
+
+err:
+ return (err < 0) ? err : count;
+}
+
+int partition_unpublish(const char *device)
+{
+ int i;
+ int count;
+ bdev_t *dev;
+ char devname[512];
+
+ count = 0;
+ for (i=0; i < 16; i++) {
+ sprintf(devname, "%sp%d", device, i);
+
+ dev = bio_open(devname);
+ if (!dev)
+ continue;
+
+ bio_unregister_device(dev);
+ bio_close(dev);
+ count++;
+ }
+
+ return count;
+}
+
diff --git a/lib/partition/rules.mk b/lib/partition/rules.mk
new file mode 100644
index 0000000..f80eb44
--- /dev/null
+++ b/lib/partition/rules.mk
@@ -0,0 +1,6 @@
+LOCAL_DIR := $(GET_LOCAL_DIR)
+
+MODULES += lib/bio
+
+OBJS += \
+ $(LOCAL_DIR)/partition.o