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>

1 files changed, 79 insertions, 0 deletions

diff --git a/include/avb_verify.h b/include/avb_verify.h
new file mode 100644
index 0000000000..428c69a2bc
--- /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 */