Add misc_writer.
bootloader_message.h currently divides /misc into four segments. The
space between 2K and 16K is reserved for vendor use (e.g. bootloader
persists flags). This CL adds a vendor tool "misc_writer", to allow
writing data to the vendor space in /misc, before getting a dedicated
HAL for accessing /misc partition (b/131775112).
Targets need to explicitly include the module, then invoke the
executable to write data. For example, the following command will write
3-byte data ("0xABCDEF") to offset 4 in vendor space (i.e. 2048 + 4 in
/misc).
$ /vendor/bin/misc_writer --vendor-space-offset 4 --hex-string 0xABCDEF
Bug: 132906936
Test: Run recovery_unit_test on crosshatch.
Test: Call the command via init.hardware.rc on crosshatch. Check that
the call finishes successfully. Then check the contents written to
/misc (`dd bs=1 skip=2048 if=/dev/block/sda2 count=32 | xxd`).
Change-Id: I79548fc63fc79b705a0320868690569c3106949f
Merged-In: I79548fc63fc79b705a0320868690569c3106949f
(cherry picked from commit 7ae01698424cc3adf635c324961b1405594f5156)
diff --git a/bootloader_message/Android.bp b/bootloader_message/Android.bp
index 5cd2132..450dad0 100644
--- a/bootloader_message/Android.bp
+++ b/bootloader_message/Android.bp
@@ -14,9 +14,8 @@
// limitations under the License.
//
-cc_library {
- name: "libbootloader_message",
- recovery_available: true,
+cc_defaults {
+ name: "libbootloader_message_defaults",
srcs: ["bootloader_message.cpp"],
cflags: [
"-Wall",
@@ -24,7 +23,25 @@
],
shared_libs: [
"libbase",
- "libfs_mgr",
+ ],
+ static_libs: [
+ "libfstab",
],
export_include_dirs: ["include"],
}
+
+cc_library {
+ name: "libbootloader_message",
+ defaults: [
+ "libbootloader_message_defaults",
+ ],
+ recovery_available: true,
+}
+
+cc_library_static {
+ name: "libbootloader_message_vendor",
+ defaults: [
+ "libbootloader_message_defaults",
+ ],
+ vendor: true,
+}
diff --git a/bootloader_message/bootloader_message.cpp b/bootloader_message/bootloader_message.cpp
index 8c1d63b..c1ebeaa 100644
--- a/bootloader_message/bootloader_message.cpp
+++ b/bootloader_message/bootloader_message.cpp
@@ -21,6 +21,7 @@
#include <string.h>
#include <string>
+#include <string_view>
#include <vector>
#include <android-base/file.h>
@@ -32,7 +33,17 @@
using android::fs_mgr::Fstab;
using android::fs_mgr::ReadDefaultFstab;
+static std::string g_misc_device_for_test;
+
+// Exposed for test purpose.
+void SetMiscBlockDeviceForTest(std::string_view misc_device) {
+ g_misc_device_for_test = misc_device;
+}
+
static std::string get_misc_blk_device(std::string* err) {
+ if (!g_misc_device_for_test.empty()) {
+ return g_misc_device_for_test;
+ }
Fstab fstab;
if (!ReadDefaultFstab(&fstab)) {
*err = "failed to read default fstab";
@@ -228,6 +239,37 @@
WIPE_PACKAGE_OFFSET_IN_MISC, err);
}
+static bool OffsetAndSizeInVendorSpace(size_t offset, size_t size) {
+ auto total_size = WIPE_PACKAGE_OFFSET_IN_MISC - VENDOR_SPACE_OFFSET_IN_MISC;
+ return size <= total_size && offset <= total_size - size;
+}
+
+bool ReadMiscPartitionVendorSpace(void* data, size_t size, size_t offset, std::string* err) {
+ if (!OffsetAndSizeInVendorSpace(offset, size)) {
+ *err = android::base::StringPrintf("Out of bound read (offset %zu size %zu)", offset, size);
+ return false;
+ }
+ auto misc_blk_device = get_misc_blk_device(err);
+ if (misc_blk_device.empty()) {
+ return false;
+ }
+ return read_misc_partition(data, size, misc_blk_device, VENDOR_SPACE_OFFSET_IN_MISC + offset,
+ err);
+}
+
+bool WriteMiscPartitionVendorSpace(const void* data, size_t size, size_t offset, std::string* err) {
+ if (!OffsetAndSizeInVendorSpace(offset, size)) {
+ *err = android::base::StringPrintf("Out of bound write (offset %zu size %zu)", offset, size);
+ return false;
+ }
+ auto misc_blk_device = get_misc_blk_device(err);
+ if (misc_blk_device.empty()) {
+ return false;
+ }
+ return write_misc_partition(data, size, misc_blk_device, VENDOR_SPACE_OFFSET_IN_MISC + offset,
+ err);
+}
+
extern "C" bool write_reboot_bootloader(void) {
std::string err;
return write_reboot_bootloader(&err);
diff --git a/bootloader_message/include/bootloader_message/bootloader_message.h b/bootloader_message/include/bootloader_message/bootloader_message.h
index 95c19ae..95dd8f4 100644
--- a/bootloader_message/include/bootloader_message/bootloader_message.h
+++ b/bootloader_message/include/bootloader_message/bootloader_message.h
@@ -28,8 +28,9 @@
// 16K - 64K Used by uncrypt and recovery to store wipe_package for A/B devices
// Note that these offsets are admitted by bootloader,recovery and uncrypt, so they
// are not configurable without changing all of them.
-static const size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
-static const size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
+constexpr size_t BOOTLOADER_MESSAGE_OFFSET_IN_MISC = 0;
+constexpr size_t VENDOR_SPACE_OFFSET_IN_MISC = 2 * 1024;
+constexpr size_t WIPE_PACKAGE_OFFSET_IN_MISC = 16 * 1024;
/* Bootloader Message (2-KiB)
*
@@ -228,6 +229,14 @@
// Write the wipe package into BCB (to offset WIPE_PACKAGE_OFFSET_IN_MISC).
bool write_wipe_package(const std::string& package_data, std::string* err);
+// Reads data from the vendor space in /misc partition, with the given offset and size. Note that
+// offset is in relative to the start of vendor space.
+bool ReadMiscPartitionVendorSpace(void* data, size_t size, size_t offset, std::string* err);
+
+// Writes the given data to the vendor space in /misc partition, at the given offset. Note that
+// offset is in relative to the start of the vendor space.
+bool WriteMiscPartitionVendorSpace(const void* data, size_t size, size_t offset, std::string* err);
+
#else
#include <stdbool.h>