1 files changed, 260 insertions, 0 deletions
diff --git a/drivers/tpm/tpm_tis_sandbox.c b/drivers/tpm/tpm_tis_sandbox.c
new file mode 100644
index 000000000..ed4b03912
--- /dev/null
+++ b/drivers/tpm/tpm_tis_sandbox.c
@@ -0,0 +1,260 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/state.h>
+#include <asm/unaligned.h>
+#include <linux/crc8.h>
+
+/* TPM NVRAM location indices. */
+#define FIRMWARE_NV_INDEX		0x1007
+#define KERNEL_NV_INDEX			0x1008
+
+#define NV_DATA_PUBLIC_PERMISSIONS_OFFSET	60
+
+/* Kernel TPM space - KERNEL_NV_INDEX, locked with physical presence */
+#define ROLLBACK_SPACE_KERNEL_VERSION	2
+#define ROLLBACK_SPACE_KERNEL_UID	0x4752574C  /* 'GRWL' */
+
+struct rollback_space_kernel {
+	/* Struct version, for backwards compatibility */
+	uint8_t struct_version;
+	/* Unique ID to detect space redefinition */
+	uint32_t uid;
+	/* Kernel versions */
+	uint32_t kernel_versions;
+	/* Reserved for future expansion */
+	uint8_t reserved[3];
+	/* Checksum (v2 and later only) */
+	uint8_t crc8;
+} __packed rollback_space_kernel;
+
+/*
+ * These numbers derive from adding the sizes of command fields as shown in
+ * the TPM commands manual.
+ */
+#define TPM_REQUEST_HEADER_LENGTH	10
+#define TPM_RESPONSE_HEADER_LENGTH	10
+
+/* These are the different non-volatile spaces that we emulate */
+enum {
+	NV_GLOBAL_LOCK,
+	NV_SEQ_FIRMWARE,
+	NV_SEQ_KERNEL,
+	NV_SEQ_COUNT,
+};
+
+/* Size of each non-volatile space */
+#define NV_DATA_SIZE		0x20
+
+/*
+ * Information about our TPM emulation. This is preserved in the sandbox
+ * state file if enabled.
+ */
+static struct tpm_state {
+	uint8_t nvdata[NV_SEQ_COUNT][NV_DATA_SIZE];
+} state;
+
+/**
+ * sandbox_tpm_read_state() - read the sandbox EC state from the state file
+ *
+ * If data is available, then blob and node will provide access to it. If
+ * not this function sets up an empty TPM.
+ *
+ * @blob: Pointer to device tree blob, or NULL if no data to read
+ * @node: Node offset to read from
+ */
+static int sandbox_tpm_read_state(const void *blob, int node)
+{
+	const char *prop;
+	int len;
+	int i;
+
+	if (!blob)
+		return 0;
+
+	for (i = 0; i < NV_SEQ_COUNT; i++) {
+		char prop_name[20];
+
+		sprintf(prop_name, "nvdata%d", i);
+		prop = fdt_getprop(blob, node, prop_name, &len);
+		if (prop && len == NV_DATA_SIZE)
+			memcpy(state.nvdata[i], prop, NV_DATA_SIZE);
+	}
+
+	return 0;
+}
+
+/**
+ * cros_ec_write_state() - Write out our state to the state file
+ *
+ * The caller will ensure that there is a node ready for the state. The node
+ * may already contain the old state, in which case it is overridden.
+ *
+ * @blob: Device tree blob holding state
+ * @node: Node to write our state into
+ */
+static int sandbox_tpm_write_state(void *blob, int node)
+{
+	int i;
+
+	/*
+	 * We are guaranteed enough space to write basic properties.
+	 * We could use fdt_add_subnode() to put each set of data in its
+	 * own node - perhaps useful if we add access informaiton to each.
+	 */
+	for (i = 0; i < NV_SEQ_COUNT; i++) {
+		char prop_name[20];
+
+		sprintf(prop_name, "nvdata%d", i);
+		fdt_setprop(blob, node, prop_name, state.nvdata[i],
+			    NV_DATA_SIZE);
+	}
+
+	return 0;
+}
+
+SANDBOX_STATE_IO(sandbox_tpm, "google,sandbox-tpm", sandbox_tpm_read_state,
+		 sandbox_tpm_write_state);
+
+static int index_to_seq(uint32_t index)
+{
+	switch (index) {
+	case FIRMWARE_NV_INDEX:
+		return NV_SEQ_FIRMWARE;
+	case KERNEL_NV_INDEX:
+		return NV_SEQ_KERNEL;
+	case 0:
+		return NV_GLOBAL_LOCK;
+	}
+
+	printf("Invalid nv index %#x\n", index);
+	return -1;
+}
+
+int tis_sendrecv(const u8 *sendbuf, size_t send_size,
+		 u8 *recvbuf, size_t *recv_len)
+{
+	struct tpm_state *tpm = &state;
+	uint32_t code, index, length, type;
+	uint8_t *data;
+	int seq;
+
+	code = get_unaligned_be32(sendbuf + sizeof(uint16_t) +
+				  sizeof(uint32_t));
+	printf("tpm: %zd bytes, recv_len %zd, cmd = %x\n", send_size,
+	       *recv_len, code);
+	print_buffer(0, sendbuf, 1, send_size, 0);
+	switch (code) {
+	case 0x65: /* get flags */
+		type = get_unaligned_be32(sendbuf + 14);
+		switch (type) {
+		case 4:
+			index = get_unaligned_be32(sendbuf + 18);
+			printf("Get flags index %#02x\n", index);
+			*recv_len = 22;
+			memset(recvbuf, '\0', *recv_len);
+			put_unaligned_be32(22, recvbuf +
+					   TPM_RESPONSE_HEADER_LENGTH);
+			data = recvbuf + TPM_RESPONSE_HEADER_LENGTH +
+					sizeof(uint32_t);
+			switch (index) {
+			case FIRMWARE_NV_INDEX:
+				break;
+			case KERNEL_NV_INDEX:
+				/* TPM_NV_PER_PPWRITE */
+				put_unaligned_be32(1, data +
+					NV_DATA_PUBLIC_PERMISSIONS_OFFSET);
+				break;
+			}
+			break;
+		case 0x11: /* TPM_CAP_NV_INDEX */
+			index = get_unaligned_be32(sendbuf + 18);
+			printf("Get cap nv index %#02x\n", index);
+			put_unaligned_be32(22, recvbuf +
+					   TPM_RESPONSE_HEADER_LENGTH);
+			break;
+		default:
+			printf("   ** Unknown 0x65 command type %#02x\n",
+			       type);
+			return -1;
+		}
+		break;
+	case 0xcd: /* nvwrite */
+		index = get_unaligned_be32(sendbuf + 10);
+		length = get_unaligned_be32(sendbuf + 18);
+		seq = index_to_seq(index);
+		if (seq < 0)
+			return -1;
+		printf("tpm: nvwrite index=%#02x, len=%#02x\n", index, length);
+		memcpy(&tpm->nvdata[seq], sendbuf + 22, length);
+		*recv_len = 12;
+		memset(recvbuf, '\0', *recv_len);
+		break;
+	case 0xcf: /* nvread */
+		index = get_unaligned_be32(sendbuf + 10);
+		length = get_unaligned_be32(sendbuf + 18);
+		seq = index_to_seq(index);
+		if (seq < 0)
+			return -1;
+		printf("tpm: nvread index=%#02x, len=%#02x\n", index, length);
+		*recv_len = TPM_RESPONSE_HEADER_LENGTH + sizeof(uint32_t) +
+					length;
+		memset(recvbuf, '\0', *recv_len);
+		put_unaligned_be32(length, recvbuf +
+				   TPM_RESPONSE_HEADER_LENGTH);
+		if (seq == NV_SEQ_KERNEL) {
+			struct rollback_space_kernel rsk;
+
+			data = recvbuf + TPM_RESPONSE_HEADER_LENGTH +
+					sizeof(uint32_t);
+			rsk.struct_version = 2;
+			rsk.uid = ROLLBACK_SPACE_KERNEL_UID;
+			rsk.kernel_versions = 0;
+			rsk.crc8 = crc8((unsigned char *)&rsk,
+					offsetof(struct rollback_space_kernel,
+						 crc8));
+			memcpy(data, &rsk, sizeof(rsk));
+		} else {
+			memcpy(recvbuf + TPM_RESPONSE_HEADER_LENGTH +
+			       sizeof(uint32_t), &tpm->nvdata[seq], length);
+		}
+		break;
+	case 0x14: /* tpm extend */
+	case 0x15: /* pcr read */
+	case 0x5d: /* force clear */
+	case 0x6f: /* physical enable */
+	case 0x72: /* physical set deactivated */
+	case 0x99: /* startup */
+	case 0x4000000a:  /* assert physical presence */
+		*recv_len = 12;
+		memset(recvbuf, '\0', *recv_len);
+		break;
+	default:
+		printf("Unknown tpm command %02x\n", code);
+		return -1;
+	}
+
+	return 0;
+}
+
+int tis_open(void)
+{
+	printf("%s\n", __func__);
+	return 0;
+}
+
+int tis_close(void)
+{
+	printf("%s\n", __func__);
+	return 0;
+}
+
+int tis_init(void)
+{
+	printf("%s\n", __func__);
+	return 0;
+}