--- /dev/null
+/*
+ * 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],
+ recvbuf + TPM_RESPONSE_HEADER_LENGTH + sizeof(uint32_t),
+ 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;
+}
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