From 7ae01698424cc3adf635c324961b1405594f5156 Mon Sep 17 00:00:00 2001 From: Tao Bao Date: Thu, 16 May 2019 14:42:42 -0700 Subject: 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 --- bootloader_message/Android.bp | 34 +++++++++++------- bootloader_message/bootloader_message.cpp | 42 ++++++++++++++++++++++ .../bootloader_message/bootloader_message.h | 13 +++++-- 3 files changed, 75 insertions(+), 14 deletions(-) (limited to 'bootloader_message') diff --git a/bootloader_message/Android.bp b/bootloader_message/Android.bp index e76305fd7..8d72a1163 100644 --- a/bootloader_message/Android.bp +++ b/bootloader_message/Android.bp @@ -14,10 +14,8 @@ // limitations under the License. // -cc_library { - name: "libbootloader_message", - recovery_available: true, - host_supported: true, +cc_defaults { + name: "libbootloader_message_defaults", srcs: ["bootloader_message.cpp"], cflags: [ "-Wall", @@ -26,24 +24,36 @@ cc_library { shared_libs: [ "libbase", ], + static_libs: [ + "libfstab", + ], export_include_dirs: ["include"], +} + +cc_library { + name: "libbootloader_message", + defaults: [ + "libbootloader_message_defaults", + ], + recovery_available: true, + host_supported: true, target: { - android: { - shared_libs: [ - "libfs_mgr", - ], - }, host: { shared_libs: [ "libcutils", // for strlcpy ], - static_libs: [ - "libfstab", - ], }, darwin: { enabled: false, }, } } + +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 331a42b2a..e684abbad 100644 --- a/bootloader_message/bootloader_message.cpp +++ b/bootloader_message/bootloader_message.cpp @@ -21,6 +21,7 @@ #include #include +#include #include #include @@ -36,7 +37,17 @@ 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"; @@ -242,6 +253,37 @@ bool write_wipe_package(const std::string& package_data, std::string* err) { 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 2207d4cb3..5c0a450fc 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) * @@ -233,6 +234,14 @@ bool read_wipe_package(std::string* package_data, size_t size, std::string* err) // 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 -- cgit v1.2.3