avb2.0: implement AVB ops
Implement AVB ops on top of existing mmc subsystem API. Currently there
is a full implementation of such operations, defined by [1]
AVB2.0 specification:
.read_from_partition() - reads N bytes from a partition identified by
a name.
.write_to_partition() - Writes N bytes to a partition identified by a name.
.validate_vbmeta_public_key() - checks if the given public ‘vbmeta’
partition is trusted.
.get_unique_guid_for_partition() - Gets the GUID for a partition identified
by a string name.
As [1] specification recommends to use tamper-evident storage for storing
rollback indexes and device state (LOCKED/UNLOCKED),
currently are only stubs instead of full implementation for these ops:
.read_rollback_index() - Gets the rollback index for a given index location
.write_rollback_index() - Sets the rollback index to a given location
.read_is_device_unlocked() - Gets where the device is unlocked
[1] https://android.googlesource.com/platform/external/avb/+/master/README.md
Signed-off-by: Igor Opaniuk <igor.opaniuk@linaro.org>
diff --git a/include/avb_verify.h b/include/avb_verify.h
new file mode 100644
index 0000000..428c69a
--- /dev/null
+++ b/include/avb_verify.h
@@ -0,0 +1,79 @@
+
+/*
+ * (C) Copyright 2018, Linaro Limited
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifndef _AVB_VERIFY_H
+#define _AVB_VERIFY_H
+
+#include <../lib/libavb/libavb.h>
+#include <mmc.h>
+
+#define ALLOWED_BUF_ALIGN 8
+
+struct AvbOpsData {
+ struct AvbOps ops;
+ int mmc_dev;
+};
+
+struct mmc_part {
+ int dev_num;
+ struct mmc *mmc;
+ struct blk_desc *mmc_blk;
+ disk_partition_t info;
+};
+
+enum mmc_io_type {
+ IO_READ,
+ IO_WRITE
+};
+
+AvbOps *avb_ops_alloc(int boot_device);
+void avb_ops_free(AvbOps *ops);
+
+/**
+ * ============================================================================
+ * I/O helper inline functions
+ * ============================================================================
+ */
+static inline uint64_t calc_offset(struct mmc_part *part, int64_t offset)
+{
+ u64 part_size = part->info.size * part->info.blksz;
+
+ if (offset < 0)
+ return part_size + offset;
+
+ return offset;
+}
+
+static inline size_t get_sector_buf_size(void)
+{
+ return (size_t)CONFIG_FASTBOOT_BUF_SIZE;
+}
+
+static inline void *get_sector_buf(void)
+{
+ return (void *)CONFIG_FASTBOOT_BUF_ADDR;
+}
+
+static inline bool is_buf_unaligned(void *buffer)
+{
+ return (bool)((uintptr_t)buffer % ALLOWED_BUF_ALIGN);
+}
+
+static inline int get_boot_device(AvbOps *ops)
+{
+ struct AvbOpsData *data;
+
+ if (ops) {
+ data = ops->user_data;
+ if (data)
+ return data->mmc_dev;
+ }
+
+ return -1;
+}
+
+#endif /* _AVB_VERIFY_H */