disk_layout: Improve documentation
In the .json file itself, add a list of changes from rev N-1 so that
people don't have to go diffing or digging through the history to
understand exactly what's different. In the readme file, update the
sentence describing how new layouts are named, and add "minios"
as a valid type.
BUG=b:196224292
TEST=CQ+1
Change-Id: Ic1c14a2fe133f6484c14692ada871e8bb19f8d93
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/3098087
Tested-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Commit-Queue: Evan Green <evgreen@chromium.org>
diff --git a/build_library/README.disk_layout b/build_library/README.disk_layout
index 0bb955a..2ca2944 100644
--- a/build_library/README.disk_layout
+++ b/build_library/README.disk_layout
@@ -10,7 +10,7 @@
To create a board specific layout that modifies this:
Create:
overlay-<board>/scripts/disk_layout.json
- list <current_year>_disk_layout.json as a parent in disk_layout.json for
+ list disk_layout_v<N>.json as a parent in disk_layout.json for
modern images, or legacy_disk_layout.json for old boards.
A layout file consists of layouts. Common types of layouts would be "base",
@@ -193,6 +193,7 @@
nand
ubi
reserved
+ minios
Legal fs_format values:
ext2
diff --git a/build_library/disk_layout_v3.json b/build_library/disk_layout_v3.json
index c34f11d..2a88548 100644
--- a/build_library/disk_layout_v3.json
+++ b/build_library/disk_layout_v3.json
@@ -1,3 +1,10 @@
+# Changes from disk_layout_v2:
+# * Introduce 128MB MINIOS-A and MINIOS-B on partitions 9 and 10, with
+# 10 being set as last_partition.
+# * Reduce OEM partition 8 from 16MB to 4MB.
+# * Remove -no-exports from ROOTFS-A squashfs options.
+# * Add powerwash data as partition 11.
+# * Delete 2gb-rootfs, 2gb-rootfs-updatable, and 4gb-rootfs.
{
# See README.disk_layout.
"parent": "common_disk_layout.json",
