From cf8427af89f47075953dad10d6ea9b848736527f Mon Sep 17 00:00:00 2001 From: David Anderson Date: Mon, 4 Nov 2019 14:08:11 -0800 Subject: bootloader_message: Add helpers for handling IBootControl MergeStatus. Move merge_status from bootloader_control_ab, which is in vendor space, to a new generic AOSP struct in system space. This will allow more devices to share the same HAL implementation. This patch also changes libboot_control to compensate for merge_status moving out of vendor space. The reference HAL library now also provides separate helper functions for managing the merge status, so devices using a custom boot control HAL can still take advantage of the new misc implementation. Bug: 139156011 Test: manual test Change-Id: I5cd824e25f9d07aad1476301def5cdc3f506b029 --- .../include/libboot_control/libboot_control.h | 23 +++++++ boot_control/libboot_control.cpp | 80 +++++++++++++++++++--- 2 files changed, 94 insertions(+), 9 deletions(-) (limited to 'boot_control') diff --git a/boot_control/include/libboot_control/libboot_control.h b/boot_control/include/libboot_control/libboot_control.h index 34a9affe1..546865887 100644 --- a/boot_control/include/libboot_control/libboot_control.h +++ b/boot_control/include/libboot_control/libboot_control.h @@ -62,5 +62,28 @@ class BootControl { unsigned int current_slot_ = 0; }; +// Helper functions to write the Virtual A/B merge status message. These are +// separate because BootControl uses bootloader_control_ab in vendor space, +// whereas the Virtual A/B merge status is in system space. A HAL might not +// use bootloader_control_ab, but may want to use the AOSP method of maintaining +// the merge status. + +// If the Virtual A/B message has not yet been initialized, then initialize it. +// This should be called when the BootControl HAL first loads. +// +// If the Virtual A/B message in misc was already initialized, true is returned. +// If initialization was attempted, but failed, false is returned, and the HAL +// should fail to load. +bool InitMiscVirtualAbMessageIfNeeded(); + +// Save the current merge status as well as the current slot. +bool SetMiscVirtualAbMergeStatus(unsigned int current_slot, + android::hardware::boot::V1_1::MergeStatus status); + +// Return the current merge status. If the saved status is SNAPSHOTTED but the +// slot hasn't changed, the status returned will be NONE. +bool GetMiscVirtualAbMergeStatus(unsigned int current_slot, + android::hardware::boot::V1_1::MergeStatus* status); + } // namespace bootable } // namespace android diff --git a/boot_control/libboot_control.cpp b/boot_control/libboot_control.cpp index ff4eaabfa..702183979 100644 --- a/boot_control/libboot_control.cpp +++ b/boot_control/libboot_control.cpp @@ -232,6 +232,10 @@ bool BootControl::Init() { UpdateAndSaveBootloaderControl(device.c_str(), &boot_ctrl); } + if (!InitMiscVirtualAbMessageIfNeeded()) { + return false; + } + num_slots_ = boot_ctrl.nb_slot; return true; } @@ -335,18 +339,15 @@ bool BootControl::IsValidSlot(unsigned int slot) { } bool BootControl::SetSnapshotMergeStatus(MergeStatus status) { - bootloader_control bootctrl; - if (!LoadBootloaderControl(misc_device_, &bootctrl)) return false; - - bootctrl.merge_status = (unsigned int)status; - return UpdateAndSaveBootloaderControl(misc_device_, &bootctrl); + return SetMiscVirtualAbMergeStatus(current_slot_, status); } MergeStatus BootControl::GetSnapshotMergeStatus() { - bootloader_control bootctrl; - if (!LoadBootloaderControl(misc_device_, &bootctrl)) return MergeStatus::UNKNOWN; - - return (MergeStatus)bootctrl.merge_status; + MergeStatus status; + if (!GetMiscVirtualAbMergeStatus(current_slot_, &status)) { + return MergeStatus::UNKNOWN; + } + return status; } const char* BootControl::GetSuffix(unsigned int slot) { @@ -356,5 +357,66 @@ const char* BootControl::GetSuffix(unsigned int slot) { return kSlotSuffixes[slot]; } +bool InitMiscVirtualAbMessageIfNeeded() { + std::string err; + misc_virtual_ab_message message; + if (!ReadMiscVirtualAbMessage(&message, &err)) { + LOG(ERROR) << "Could not read merge status: " << err; + return false; + } + + if (message.version == MISC_VIRTUAL_AB_MESSAGE_VERSION) { + // Already initialized. + return true; + } + + message = {}; + message.version = MISC_VIRTUAL_AB_MESSAGE_VERSION; + if (!WriteMiscVirtualAbMessage(message, &err)) { + LOG(ERROR) << "Could not write merge status: " << err; + return false; + } + return true; +} + +bool SetMiscVirtualAbMergeStatus(unsigned int current_slot, + android::hardware::boot::V1_1::MergeStatus status) { + std::string err; + misc_virtual_ab_message message; + + if (!ReadMiscVirtualAbMessage(&message, &err)) { + LOG(ERROR) << "Could not read merge status: " << err; + return false; + } + + message.merge_status = static_cast(status); + message.source_slot = current_slot; + if (!WriteMiscVirtualAbMessage(message, &err)) { + LOG(ERROR) << "Could not write merge status: " << err; + return false; + } + return true; +} + +bool GetMiscVirtualAbMergeStatus(unsigned int current_slot, + android::hardware::boot::V1_1::MergeStatus* status) { + std::string err; + misc_virtual_ab_message message; + + if (!ReadMiscVirtualAbMessage(&message, &err)) { + LOG(ERROR) << "Could not read merge status: " << err; + return false; + } + + // If the slot reverted after having created a snapshot, then the snapshot will + // be thrown away at boot. Thus we don't count this as being in a snapshotted + // state. + *status = static_cast(message.merge_status); + if (*status == MergeStatus::SNAPSHOTTED && current_slot == message.source_slot) { + *status = MergeStatus::NONE; + } + return true; +} + } // namespace bootable } // namespace android -- cgit v1.2.3