From 401650636c3a9c082bdc5f69fef3091215ee6150 Mon Sep 17 00:00:00 2001
From: Collin Wright <collinwright@google.com>
Date: Wed, 8 Jul 2026 18:45:10 +0000
Subject: [PATCH] Add tpm startup subcommand to htool

---
 examples/htool.c     |  6 ++++++
 examples/htool_tpm.c | 28 ++++++++++++++++++++++++++++
 examples/htool_tpm.h |  2 ++
 3 files changed, 36 insertions(+)

diff --git a/examples/htool.c b/examples/htool.c
index 0a3c758..04dcbbc 100644
--- a/examples/htool.c
+++ b/examples/htool.c
@@ -2067,6 +2067,12 @@ static const struct htool_cmd CMDS[] = {
         .params = (const struct htool_param[]){{}},
         .func = htool_get_tpm_mode,
     },
+    {
+        .verbs = (const char*[]){"tpm", "startup", NULL},
+        .desc = "Send TPM2_Startup(CLEAR) command to initialize the TPM.",
+        .params = (const struct htool_param[]){{}},
+        .func = htool_tpm_startup,
+    },
     {
         .verbs = (const char*[]){"tpm", "set_mode", "disabled", NULL},
         .desc = "Set the TPM mode to DISABLED.",
diff --git a/examples/htool_tpm.c b/examples/htool_tpm.c
index ca7f0fa..4d67d87 100644
--- a/examples/htool_tpm.c
+++ b/examples/htool_tpm.c
@@ -86,3 +86,31 @@ int htool_get_tpm_mode(const struct htool_invocation* inv) {
 
   return 0;
 }
+
+int htool_tpm_startup(const struct htool_invocation* inv) {
+  struct libhoth_device* dev = htool_libhoth_device();
+  if (!dev) {
+    return -1;
+  }
+
+  // Standard 12-byte TPM2_Startup(CLEAR) command packet
+  static const uint8_t req[12] = {
+      0x80, 0x01,             // TPM_ST_NO_SESSIONS
+      0x00, 0x00, 0x00, 0x0c, // paramSize = 12
+      0x00, 0x00, 0x01, 0x44, // TPM_CC_Startup
+      0x00, 0x00              // TPM_SU_CLEAR
+  };
+
+  uint8_t resp[32];
+  size_t resp_size = 0;
+  int ret = libhoth_hostcmd_exec(
+      dev, HOTH_CMD_BOARD_SPECIFIC_BASE + HOTH_PRV_CMD_HAVEN_TPM, 0, req,
+      sizeof(req), resp, sizeof(resp), &resp_size);
+  if (ret) {
+    htool_report_error("tpm startup", ret);
+    return ret;
+  }
+
+  printf("TPM2_Startup(CLEAR) sent successfully.\n");
+  return 0;
+}
diff --git a/examples/htool_tpm.h b/examples/htool_tpm.h
index 6fe0129..ddd00b8 100644
--- a/examples/htool_tpm.h
+++ b/examples/htool_tpm.h
@@ -23,6 +23,7 @@ extern "C" {
 
 #define HOTH_PRV_CMD_SET_TPM_MODE 0x0051
 #define HOTH_PRV_CMD_GET_TPM_MODE 0x0052
+#define HOTH_PRV_CMD_HAVEN_TPM 0x0033
 
 enum ec_tpm_mode {
   TPM_MODE_DISABLED = 0,  // Turn the TPM off: typically used to turn off one
@@ -38,6 +39,7 @@ struct tpm_mode {
 
 int htool_set_tpm_mode(const struct htool_invocation* inv);
 int htool_get_tpm_mode(const struct htool_invocation* inv);
+int htool_tpm_startup(const struct htool_invocation* inv);
 
 #ifdef __cplusplus
 }