[PATCH 06/13] binman: android_boot: vendor-dt support
Sam Day via B4 Relay
devnull+me.samcday.com at kernel.org
Sat Jun 6 02:52:40 CEST 2026
From: Sam Day <me at samcday.com>
There's many Android bootloaders out there that expect non-standard
abootimgs. Samsung and Qualcomm, and likely many others. This quirk has
been codified in the widely used osm0sis fork/rewrite of mkbootimg.
Presumably, these vendor-specific abootimgs were conceived before the v2
format was widely available or specified. The evidence for this is their
hijacking of the header_version field to specify the length of a payload
that follows the main abootimg.
At least QCDT and DTBH (both of which will be implemented as binman
etypes in following commits) use this approach.
Link: https://github.com/osm0sis/mkbootimg
Signed-off-by: Sam Day <me at samcday.com>
---
tools/binman/etype/android_boot.py | 38 ++++++++++++++++++++--
tools/binman/ftest.py | 11 ++++++-
.../binman/test/vendor/android_boot_vendor_dt.dts | 27 +++++++++++++++
3 files changed, 73 insertions(+), 3 deletions(-)
diff --git a/tools/binman/etype/android_boot.py b/tools/binman/etype/android_boot.py
index adf8248ee12..fa5dd746411 100644
--- a/tools/binman/etype/android_boot.py
+++ b/tools/binman/etype/android_boot.py
@@ -40,6 +40,9 @@ class Entry_android_boot(Entry_section):
A kernel payload, optional ramdisk payload can be supplied. A DTB payload
can also be provided when header_version == v2.
+ Vendor-specific payloads are also supported. These are non-standard
+ v0 images with a special DT container format appended.
+
Properties / Entry arguments:
- header-version: Android boot image header version, must be 0 or 2,
defaults to 0
@@ -52,11 +55,13 @@ class Entry_android_boot(Entry_section):
- os-version: Encoded Android OS version and patch level, defaults to 0
- boot-name: Android boot image board name
- cmdline: Android boot command line
+ used by header version 0 only
This entry uses the following subnodes:
- kernel: section containing the executable payload
- dtb: section containing the DTB payload, used by header version 2 only
- ramdisk: optional section containing a ramdisk payload
+ - vendor-dt: legacy vendor DT payload, used by header version 0 only
Example::
A v2 abootimg with control FDT placed in the DTB section:
@@ -117,6 +122,7 @@ class Entry_android_boot(Entry_section):
self.os_version = fdt_util.GetInt(self._node, 'os-version', 0)
self.boot_name = fdt_util.GetString(self._node, 'boot-name', '')
self.cmdline = fdt_util.GetString(self._node, 'cmdline', '')
+ self.vendor_dt_node = self._node.FindNode('vendor-dt')
if self.header_version not in (0, 2):
self.Raise('Only Android boot image header versions 0 and 2 are '
@@ -131,17 +137,26 @@ class Entry_android_boot(Entry_section):
self.Raise('page-size must fit the Android boot image header')
if 'dtb' in self._entries:
self.Raise("Subnode 'dtb' requires header-version 2")
+ if self.vendor_dt_node and self.os_version:
+ self.Raise("os_version not allowed when vendor-dt is in use")
else:
# v2
if self.page_size < BOOT_IMAGE_HEADER_V2_SIZE:
self.Raise('page-size must fit the Android boot image header')
if 'dtb' not in self._entries:
self.Raise("Missing required subnode 'dtb'")
+ if self.vendor_dt_node:
+ self.Raise("Subnode 'vendor-dt' requires header-version 0")
def ReadEntries(self):
for node in self._node.subnodes:
if self.IsSpecialSubnode(node):
continue
+
+ if node.name == 'vendor-dt':
+ self._ReadVendorDtEntries(node)
+ continue
+
if node.name not in ('kernel', 'ramdisk', 'dtb'):
self.Raise("Unexpected subnode '%s'" % node.name)
@@ -152,6 +167,15 @@ class Entry_android_boot(Entry_section):
entry.SetPrefix(self._name_prefix)
self._entries[node.name] = entry
+ def _ReadVendorDtEntries(self, vendor_dt_node):
+ entry = Entry.Create(self, vendor_dt_node, etype='section',
+ expanded=self.GetImage().use_expanded,
+ missing_etype=self.GetImage().missing_etype)
+ entry.page_size = fdt_util.GetInt(self._node, 'page-size', 2048)
+ entry.ReadNode()
+ entry.SetPrefix(self._name_prefix)
+ self._entries[vendor_dt_node.name] = entry
+
def _GetIntCells(self, propname, default):
prop = self._node.props.get(propname)
if not prop:
@@ -243,11 +267,18 @@ class Entry_android_boot(Entry_section):
fdt.pack()
return bytes(fdt.as_bytearray())
+ def _BuildVendorDt(self, required):
+ if not self.vendor_dt_node:
+ return b''
+ return self._GetEntryData('vendor-dt', required)
+
def _BuildV0SectionData(self, required):
kernel = self._GetEntryData('kernel', required)
if kernel is None:
return None
-
+ vendor_dt = self._BuildVendorDt(required)
+ if vendor_dt is None:
+ return None
ramdisk = self._GetOptionalEntryData('ramdisk', required)
if ramdisk is None:
return None
@@ -258,6 +289,8 @@ class Entry_android_boot(Entry_section):
BOOT_ARGS_SIZE)
boot_id_payloads = [kernel, ramdisk, b'']
+ if self.vendor_dt_node:
+ boot_id_payloads.append(vendor_dt)
image_id = self._BootId(*boot_id_payloads)
header = struct.pack(BOOT_IMAGE_HEADER_V0,
@@ -270,7 +303,7 @@ class Entry_android_boot(Entry_section):
0, # second_offset
self._GetAddr(self.tags_offset, 'tags'),
self.page_size,
- self.header_version,
+ len(vendor_dt),
self.os_version,
boot_name,
cmdline,
@@ -280,6 +313,7 @@ class Entry_android_boot(Entry_section):
image += _pad(header, self.page_size)
image += _pad(kernel, self.page_size)
image += _pad(ramdisk, self.page_size)
+ image += _pad(vendor_dt, self.page_size)
return bytes(image)
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index e92a231417b..80219e519f6 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -5662,7 +5662,16 @@ fdt fdtmap Extract the devicetree blob from the fdtmap
self.assertEqual(U_BOOT_DTB_DATA,
data[0x1000:0x1000 + len(U_BOOT_DTB_DATA)])
- self.assertEqual(U_BOOT_DATA, data[0x800:0x800 + len(U_BOOT_DATA)])
+ def testAndroidBootVendorDt(self):
+ """Test that android-boot can embed an arbitrary vendor-dt section"""
+ data = self._DoReadFile('vendor/android_boot_vendor_dt.dts')
+ header = struct.unpack_from('<8s10I16s512s32s', data, 0)
+ vendor_dt = b'howdy'
+ self.assertEqual(len(vendor_dt), header[9])
+ self.assertEqual(0, header[10])
+ self.assertEqual(self._AndroidBootId(U_BOOT_DATA, b'\0', b'',
+ vendor_dt), header[13])
+ self.assertEqual(vendor_dt, data[0x1800:0x1805])
def testFitFdtOper(self):
"""Check handling of a specified FIT operation"""
diff --git a/tools/binman/test/vendor/android_boot_vendor_dt.dts b/tools/binman/test/vendor/android_boot_vendor_dt.dts
new file mode 100644
index 00000000000..194396a0880
--- /dev/null
+++ b/tools/binman/test/vendor/android_boot_vendor_dt.dts
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0+
+/dts-v1/;
+/ {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ binman {
+ android-boot {
+ header-version = <0>;
+ kernel {
+ u-boot {
+ no-expanded;
+ };
+ };
+ ramdisk {
+ fill {
+ size = <1>;
+ };
+ };
+ vendor-dt {
+ text {
+ size = <5>;
+ text = "howdy";
+ };
+ };
+ };
+ };
+};
--
2.54.0
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