Merge lp:~salgado/linaro-image-tools/port-more-create_partitions into lp:linaro-image-tools/11.11

[Guilherme Salgado]

Port a few more bits of create_partitions to python.

The remaining bits depend on many other things being ported as well, as they set variables used elsewhere and register loopback devices (using yet another shell variable) to make sure they are cleaned up.

[James Westby (james-w)]

Hi,

eval isn't pretty, but it is simple, not a security problem here and won't
be around for long anyway.

Thanks,

James

review: Approve

[Guilherme Salgado (salgado)]

Yeah, eval is just a hack while we need to pass data back from python to the shell script. It will go away soon

Thanks for the review!

[lp:~salgado/linaro-image-tools/port-more-create_partitions]

182. By Guilherme Salgado on 2010-12-09

merge parent branch

=== modified file 'linaro-media-create'
--- linaro-media-create	2010-12-09 20:03:10 +0000
+++ linaro-media-create	2010-12-09 20:03:10 +0000
@@ -442,18 +442,14 @@
       "${DEVICE-$IMAGE_FILE}" "$FAT_SIZE" "$HEADS" "$SECTORS" "$CYLINDER_ARG"
 
   if [ "${IMAGE_FILE}" ]; then
-  VFATOFFSET=$(($(LC_ALL=C fdisk -l -u "$IMAGE_FILE" | grep FAT | awk '{print $3}')*512))
-  VFATSIZE2=$(($(LC_ALL=C fdisk -l -u "$IMAGE_FILE" | grep FAT | awk '{print $4}')))
-  VFATSIZE1=$(($(LC_ALL=C fdisk -l -u "$IMAGE_FILE" | grep FAT | awk '{print $3}')))
-  VFATSIZE=$((((VFATSIZE2+1-VFATSIZE1)/2)*1024))
-  ROOTOFFSET=$(($(LC_ALL=C fdisk -l -u "$IMAGE_FILE" | grep Linux | awk '{print $2}')*512))
-  ROOTSIZE2=$(($(LC_ALL=C fdisk -l -u "$IMAGE_FILE" | grep Linux | awk '{print $3}')))
-  ROOTSIZE1=$(($(LC_ALL=C fdisk -l -u "$IMAGE_FILE" | grep Linux | awk '{print $2}')))
-  ROOTSIZE=$((((ROOTSIZE2+1-ROOTSIZE1)/2)*1024))
-  BOOTFS=$(sudo losetup -f --show "$IMAGE_FILE" --offset $VFATOFFSET --sizelimit $VFATSIZE)
-  register_loopback "$BOOTFS"
-  ROOTFS=$(sudo losetup -f --show "$IMAGE_FILE" --offset $ROOTOFFSET --sizelimit $ROOTSIZE)
-  register_loopback "$ROOTFS"
+    sizes_and_offsets=$(python -m media_create.partition_size "${IMAGE_FILE}")
+    eval $sizes_and_offsets
+    BOOTFS=$(sudo losetup -f --show "$IMAGE_FILE" --offset $VFATOFFSET \
+             --sizelimit $VFATSIZE)
+    register_loopback "$BOOTFS"
+    ROOTFS=$(sudo losetup -f --show "$IMAGE_FILE" --offset $ROOTOFFSET \
+             --sizelimit $ROOTSIZE)
+    register_loopback "$ROOTFS"
   fi
 }
 

=== added file 'media_create/partition_size.py'
--- media_create/partition_size.py	1970-01-01 00:00:00 +0000
+++ media_create/partition_size.py	2010-12-09 20:03:10 +0000
@@ -0,0 +1,42 @@
+import sys
+
+from parted import (
+    Device,
+    Disk,
+    )
+
+
+def calculate_partition_size_and_offset(device):
+    """Return the size and offset of the boot and root partitions.
+
+    Both the size and offset are in sectors.
+
+    :param device: A string containing the path to the device.
+    :return: A 4-tuple containing the offset and size of the boot partition
+        followed by the offset and size of the root partition.
+    """
+    disk = Disk(Device(device))
+    vfat_partition = None
+    for partition in disk.partitions:
+        if 'boot' in partition.getFlagsAsString():
+            geometry = partition.geometry
+            vfat_offset = geometry.start * 512
+            vfat_size = geometry.length * 512
+            vfat_partition = partition
+
+    assert vfat_partition is not None, (
+        "Couldn't find boot partition on %s" % device)
+    linux_partition = vfat_partition.nextPartition()
+    geometry = linux_partition.geometry
+    linux_offset = geometry.start * 512
+    linux_size = geometry.length * 512
+    return vfat_size, vfat_offset, linux_size, linux_offset
+
+
+if __name__ == "__main__":
+    vsize, voffset, rsize, roffset = calculate_partition_size_and_offset(
+        sys.argv[1])
+    # These values need to be assigned to shell variables in our script, so we
+    # make its job easier by printing something it can pass on to eval.
+    print "VFATSIZE=%s VFATOFFSET=%s ROOTSIZE=%s ROOTOFFSET=%s" % (
+        vsize, voffset, rsize, roffset)

=== modified file 'media_create/tests/test_media_create.py'
--- media_create/tests/test_media_create.py	2010-12-09 20:03:10 +0000
+++ media_create/tests/test_media_create.py	2010-12-09 20:03:10 +0000
@@ -17,6 +17,7 @@
     create_partitions,
     run_sfdisk_commands,
     )
+from media_create.partition_size import calculate_partition_size_and_offset
 from media_create.populate_boot import (
     make_boot_script,
     make_uImage,
@@ -301,3 +302,20 @@
             cmd_runner.SubcommandNonZeroReturnValue,
             run_sfdisk_commands,
             ',1,0xDA', 5, 63, '', tempfile, as_root=False)
+
+
+class TestCalculatePartitionSizeAndOffset(TestCaseWithFixtures):
+
+    def test_foo(self):
+        tempfile = self.createTempFileAsFixture()
+        cmd_runner.run(['qemu-img', 'create', '-f', 'raw', tempfile, '10M'],
+                       stdout=subprocess.PIPE)
+        stdout, stderr = run_sfdisk_commands(
+            ',1,0x0C,*\n,,,-', 5, 63, '', tempfile, as_root=False)
+        self.assertIn('Successfully wrote the new partition table', stdout)
+
+        vfat_size, vfat_offset, linux_size, linux_offset = (
+            calculate_partition_size_and_offset(tempfile))
+        self.assertEqual(
+            [129024L, 32256L, 10321920L, 161280L],
+            [vfat_size, vfat_offset, linux_size, linux_offset])