feat(plat/imx/imx8m/imx8mm): add support for measured boot
Add helper functions to generate event log for imx8mm
when MEASURED_BOOT=1.
Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Change-Id: Ifc947d749055787fbda0b39170aa2eb8865b7802
diff --git a/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c b/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c
new file mode 100644
index 0000000..8b2fdd6
--- /dev/null
+++ b/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2022, Linaro.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_helpers.h>
+#if MEASURED_BOOT
+#include <common/desc_image_load.h>
+#endif
+#include <common/fdt_wrappers.h>
+#include <libfdt.h>
+
+#define DTB_PROP_HW_LOG_ADDR "tpm_event_log_addr"
+#define DTB_PROP_HW_LOG_SIZE "tpm_event_log_size"
+
+#if MEASURED_BOOT
+
+static int imx8m_event_log_fdt_init_overlay(uintptr_t dt_base, int dt_size)
+{
+ int ret;
+ int offset;
+ void *dtb = (void *)dt_base;
+
+ ret = fdt_create_empty_tree(dtb, dt_size);
+ if (ret < 0) {
+ ERROR("cannot create empty dtb tree: %s\n",
+ fdt_strerror(ret));
+ return ret;
+ }
+
+ offset = fdt_path_offset(dtb, "/");
+ if (offset < 0) {
+ ERROR("cannot find root of the tree: %s\n",
+ fdt_strerror(offset));
+ return offset;
+ }
+
+ offset = fdt_add_subnode(dtb, offset, "fragment@0");
+ if (offset < 0) {
+ ERROR("cannot add fragment node: %s\n",
+ fdt_strerror(offset));
+ return offset;
+ }
+
+ ret = fdt_setprop_string(dtb, offset, "target-path", "/");
+ if (ret < 0) {
+ ERROR("cannot set target-path property: %s\n",
+ fdt_strerror(ret));
+ return ret;
+ }
+
+ offset = fdt_add_subnode(dtb, offset, "__overlay__");
+ if (offset < 0) {
+ ERROR("cannot add __overlay__ node: %s\n",
+ fdt_strerror(offset));
+ return ret;
+ }
+
+ offset = fdt_add_subnode(dtb, offset, "tpm_event_log");
+ if (offset < 0) {
+ ERROR("cannot add tpm_event_log node: %s\n",
+ fdt_strerror(offset));
+ return offset;
+ }
+
+ ret = fdt_setprop_string(dtb, offset, "compatible",
+ "arm,tpm_event_log");
+ if (ret < 0) {
+ ERROR("cannot set compatible property: %s\n",
+ fdt_strerror(ret));
+ return ret;
+ }
+
+ ret = fdt_setprop_u64(dtb, offset, "tpm_event_log_addr", 0);
+ if (ret < 0) {
+ ERROR("cannot set tpm_event_log_addr property: %s\n",
+ fdt_strerror(ret));
+ return ret;
+ }
+
+ ret = fdt_setprop_u32(dtb, offset, "tpm_event_log_size", 0);
+ if (ret < 0) {
+ ERROR("cannot set tpm_event_log_size property: %s\n",
+ fdt_strerror(ret));
+ return ret;
+ }
+
+ return ret;
+}
+
+/*
+ * Write the Event Log address and its size in the DTB.
+ *
+ * This function is supposed to be called only by BL2.
+ *
+ * Returns:
+ * 0 = success
+ * < 0 = error
+ */
+static int imx8m_set_event_log_info(uintptr_t config_base,
+ uintptr_t log_addr, size_t log_size)
+{
+ /* As libfdt uses void *, we can't avoid this cast */
+ void *dtb = (void *)config_base;
+ const char *compatible_tpm = "arm,tpm_event_log";
+ uint64_t base = cpu_to_fdt64(log_addr);
+ uint32_t sz = cpu_to_fdt32(log_size);
+ int err, node;
+
+ err = fdt_open_into(dtb, dtb, PLAT_IMX8M_DTO_MAX_SIZE);
+ if (err < 0) {
+ ERROR("Invalid Device Tree at %p: error %d\n", dtb, err);
+ return err;
+ }
+
+ /*
+ * Verify that the DTB is valid, before attempting to write to it,
+ * and get the DTB root node.
+ */
+
+ /* Check if the pointer to DT is correct */
+ err = fdt_check_header(dtb);
+ if (err < 0) {
+ WARN("Invalid DTB file passed\n");
+ return err;
+ }
+
+ /*
+ * Find the TPM node in device tree.
+ */
+ node = fdt_node_offset_by_compatible(dtb, -1, compatible_tpm);
+ if (node < 0) {
+ ERROR("The compatible property '%s' not%s", compatible_tpm,
+ " found in the config\n");
+ return node;
+ }
+
+ err = fdt_setprop(dtb, node, DTB_PROP_HW_LOG_ADDR, &base, 8);
+ if (err < 0) {
+ ERROR("Failed to add log addr err %d\n", err);
+ return err;
+ }
+
+ err = fdt_setprop(dtb, node, DTB_PROP_HW_LOG_SIZE, &sz, 4);
+ if (err < 0) {
+ ERROR("Failed to add log addr err %d\n", err);
+ return err;
+ }
+
+ err = fdt_pack(dtb);
+ if (err < 0) {
+ ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, err);
+ return err;
+ }
+
+ /*
+ * Ensure that the info written to the DTB is visible
+ * to other images.
+ */
+ flush_dcache_range(config_base, fdt_totalsize(dtb));
+
+ return err;
+}
+
+/*
+ * This function writes the Event Log address and its size
+ * in the QEMU DTB.
+ *
+ * This function is supposed to be called only by BL2.
+ *
+ * Returns:
+ * 0 = success
+ * < 0 = error
+ */
+int imx8m_set_nt_fw_info(size_t log_size, uintptr_t *ns_log_addr)
+{
+ uintptr_t ns_addr;
+ int err;
+
+ assert(ns_log_addr != NULL);
+
+ ns_addr = PLAT_IMX8M_DTO_BASE + PLAT_IMX8M_DTO_MAX_SIZE;
+
+ imx8m_event_log_fdt_init_overlay(PLAT_IMX8M_DTO_BASE,
+ PLAT_IMX8M_DTO_MAX_SIZE);
+
+ /* Write the Event Log address and its size in the DTB */
+ err = imx8m_set_event_log_info(PLAT_IMX8M_DTO_BASE,
+ ns_addr, log_size);
+
+ /* Return Event Log address in Non-secure memory */
+ *ns_log_addr = (err < 0) ? 0UL : ns_addr;
+ return err;
+}
+
+#endif /* MEASURED_BOOT */