[rom_ext] Add AST patching to rom_ext.

Add a mechanism to patch the AST configuration in the rom_ext stage. The
data is loaded from the `kFlashCtrlInfoPageFactoryId` info page. The
configuration is only applied if the first two words read from flash are
not 00s or UINT32_t.

Signed-off-by: Miguel Osorio <[email protected]>

sw/device/silicon_creator/lib/drivers/BUILD

@@ -106,9 +106,11 @@ cc_library(
     srcs = ["ast.c"],
     hdrs = ["ast.h"],
     deps = [
+        ":flash_ctrl",
         ":lifecycle",
         ":otp",
         "//hw/ip/otp_ctrl/data:otp_ctrl_regs",
+        "//hw/top_earlgrey/ip/ast/data:ast_regs",
         "//hw/top_earlgrey/ip/sensor_ctrl/data:sensor_ctrl_regs",
         "//hw/top_earlgrey/sw/autogen:top_earlgrey",
         "//sw/device/lib/arch:device",

sw/device/silicon_creator/lib/drivers/ast.c

@@ -8,19 +8,43 @@
 #include "sw/device/lib/base/abs_mmio.h"
 #include "sw/device/lib/base/csr.h"
 #include "sw/device/lib/base/multibits.h"
+#include "sw/device/silicon_creator/lib/drivers/flash_ctrl.h"
 #include "sw/device/silicon_creator/lib/drivers/otp.h"
 
+#include "ast_regs.h"  // Generated.
 #include "hw/top_earlgrey/sw/autogen/top_earlgrey.h"
-#include "otp_ctrl_regs.h"
-#include "sensor_ctrl_regs.h"
+#include "otp_ctrl_regs.h"     // Generated.
+#include "sensor_ctrl_regs.h"  // Generated.
 
 #ifndef OT_PLATFORM_RV32
 // Provide a definition for off-target unit tests.
 const uint32_t kAstCheckPollCpuCycles = 10000;
 #endif
 
 enum {
-  kBase = TOP_EARLGREY_SENSOR_CTRL_AON_BASE_ADDR,
+  kBaseSensorCtrl = TOP_EARLGREY_SENSOR_CTRL_AON_BASE_ADDR,
+  kBaseAst = TOP_EARLGREY_AST_BASE_ADDR,
+
+  /**
+   * AST Calibration Data Size - Bank 0, Page 0
+   *
+   * Number of AST calibration words that will be stored in flash / OTP.
+   *
+   * Must match `kFlashInfoAstCalibrationDataSizeIn32BitWords` in
+   * //sw/device/silicon_creator/manuf/lib/flash_info_fields.h.
+   */
+  kAstCalibrationDataSizeIn32BitWords =
+      (AST_REGAL_REG_OFFSET + sizeof(uint32_t)) / sizeof(uint32_t),
+
+  /**
+   * The starting offset of the AST calibration data within the
+   * `kFlashCtrlInfoPageFactoryId` info flash page.
+   *
+   * Must be compatible to the `kFlashInfoFieldAstCalibrationData` byte offset
+   * in //sw/device/silicon_creator/manuf/lib/flash_info_fields.c.
+   */
+  kAstCalibrationDataInfoFlashByteOffset =
+      OTP_CTRL_PARAM_DEVICE_ID_SIZE + OTP_CTRL_PARAM_MANUF_STATE_SIZE,
 };
 
 rom_error_t ast_check(lifecycle_state_t lc_state) {
@@ -76,7 +100,8 @@ rom_error_t ast_check(lifecycle_state_t lc_state) {
 
 OT_WARN_UNUSED_RESULT
 static bool done_bit_get(void) {
-  uint32_t reg = abs_mmio_read32(kBase + SENSOR_CTRL_STATUS_REG_OFFSET);
+  uint32_t reg =
+      abs_mmio_read32(kBaseSensorCtrl + SENSOR_CTRL_STATUS_REG_OFFSET);
   return bitfield_bit32_read(reg, SENSOR_CTRL_STATUS_AST_INIT_DONE_BIT);
 }
 
@@ -96,3 +121,56 @@ hardened_bool_t ast_init_done(void) {
   }
   return res;
 }
+
+/**
+ * Loads AST patch from kFlashCtrlInfoPageFactoryId page.
+ *
+ * The `ast_data` offset must be equivalent to the one used in
+ * //sw/device/silicon_creator/manuf/lib/ast_program.c.
+ *
+ * The info flash configuration must also be the same used to program the page,
+ * otherwise the data read will be garbled.
+ *
+ * @param[out] ast_data Pointer to the buffer used to store the data read.
+ *
+ * @return The result of the operation.
+ */
+OT_WARN_UNUSED_RESULT
+static rom_error_t load_ast_config_from_flash(uint32_t *ast_data) {
+  flash_ctrl_info_perms_set(&kFlashCtrlInfoPageFactoryId,
+                            (flash_ctrl_perms_t){
+                                .read = kMultiBitBool4True,
+                                .write = kMultiBitBool4False,
+                                .erase = kMultiBitBool4False,
+                            });
+  flash_ctrl_info_cfg_set(&kFlashCtrlInfoPageFactoryId,
+                          (flash_ctrl_cfg_t){
+                              .scrambling = kMultiBitBool4False,
+                              .ecc = kMultiBitBool4True,
+                              .he = kMultiBitBool4False,
+                          });
+  return flash_ctrl_info_read(&kFlashCtrlInfoPageFactoryId,
+                              kAstCalibrationDataInfoFlashByteOffset,
+                              kAstCalibrationDataSizeIn32BitWords, ast_data);
+}
+
+rom_error_t ast_patch(lifecycle_state_t lc_state) {
+  uint32_t ast_data[kAstCalibrationDataSizeIn32BitWords];
+  HARDENED_RETURN_IF_ERROR(load_ast_config_from_flash(ast_data));
+
+  // Skip patching logic if either of the first two words don't seem to be
+  // configured.
+  if (ast_data[0] == 0 || ast_data[0] == UINT32_MAX) {
+    return ast_check(lc_state);
+  }
+
+  if (ast_data[1] == 0 || ast_data[1] == UINT32_MAX) {
+    return ast_check(lc_state);
+  }
+
+  for (size_t i = 0; i < kAstCalibrationDataSizeIn32BitWords; ++i) {
+    abs_mmio_write32(kBaseAst + i * sizeof(uint32_t), ast_data[i]);
+  }
+
+  return ast_check(lc_state);
+}

sw/device/silicon_creator/lib/drivers/ast.h

@@ -16,6 +16,8 @@ extern "C" {
 /**
  * Check that the AST is in the expected state.
  *
+ * @param lc_state The current life cycle state.
+ *
  * @return an error if the AST is not in the expected state.
  */
 OT_WARN_UNUSED_RESULT
@@ -30,6 +32,22 @@ rom_error_t ast_check(lifecycle_state_t lc_state);
 OT_WARN_UNUSED_RESULT
 hardened_bool_t ast_init_done(void);
 
+/**
+ * Conditionally patch the AST registers using data stored in an info partition
+ * used to store manufacturing information.
+ *
+ * The patch is skipped if any of the first to AST words stored in the info
+ * partition are equivalent to 0 or UINT32_MAX.
+ *
+ * This function also calls `ast_check()` before returning.
+ *
+ * @param lc_state The current life cycle state.
+ *
+ * @return an error if the AST is not in the expected state.
+ */
+OT_WARN_UNUSED_RESULT
+rom_error_t ast_patch(lifecycle_state_t lc_state);
+
 #ifdef __cplusplus
 }
 #endif

sw/device/silicon_creator/rom_ext/BUILD

@@ -219,6 +219,7 @@ cc_library(
         "//sw/device/silicon_creator/lib/base:sec_mmio",
         "//sw/device/silicon_creator/lib/base:static_critical",
         "//sw/device/silicon_creator/lib/boot_svc:boot_svc_msg",
+        "//sw/device/silicon_creator/lib/drivers:ast",
         "//sw/device/silicon_creator/lib/drivers:flash_ctrl",
         "//sw/device/silicon_creator/lib/drivers:hmac",
         "//sw/device/silicon_creator/lib/drivers:ibex",
@@ -234,14 +235,14 @@ cc_library(
     ],
 )
 
-manifest({
+manifest(d = {
     "name": "manifest_standard",
     "address_translation": hex(CONST.HARDENED_FALSE),
     "identifier": hex(CONST.ROM_EXT),
     "visibility": ["//visibility:public"],
 })
 
-manifest({
+manifest(d = {
     "name": "manifest_virtual",
     "address_translation": hex(CONST.HARDENED_TRUE),
     "identifier": hex(CONST.ROM_EXT),
@@ -301,7 +302,7 @@ opentitan_binary(
     ],
 )
 
-manifest({
+manifest(d = {
     "name": "manifest_bad_address_translation",
     "address_translation": "0",
     "identifier": hex(CONST.ROM_EXT),

sw/device/silicon_creator/rom_ext/rom_ext.c

@@ -21,6 +21,7 @@
 #include "sw/device/silicon_creator/lib/boot_svc/boot_svc_header.h"
 #include "sw/device/silicon_creator/lib/boot_svc/boot_svc_msg.h"
 #include "sw/device/silicon_creator/lib/dbg_print.h"
+#include "sw/device/silicon_creator/lib/drivers/ast.h"
 #include "sw/device/silicon_creator/lib/drivers/flash_ctrl.h"
 #include "sw/device/silicon_creator/lib/drivers/hmac.h"
 #include "sw/device/silicon_creator/lib/drivers/ibex.h"
@@ -106,16 +107,19 @@ void rom_ext_check_rom_expectations(void) {
   sec_mmio_check_values(rnd_uint32());
 }
 
-void rom_ext_init(void) {
+OT_WARN_UNUSED_RESULT
+static rom_error_t rom_ext_init(void) {
   sec_mmio_next_stage_init();
-
   lc_state = lifecycle_state_get();
-
-  // TODO: Verify ePMP expectations from ROM.
-
   pinmux_init();
   // Configure UART0 as stdout.
   uart_init(kUartNCOValue);
+
+  // TODO: Verify ePMP expectations from ROM.
+
+  // Conditionally patch AST and check that it is in the expected state.
+  HARDENED_RETURN_IF_ERROR(ast_patch(lc_state));
+  return kErrorOk;
 }
 
 void rom_ext_sram_exec(hardened_bool_t enable) {
@@ -530,7 +534,7 @@ static rom_error_t rom_ext_try_boot(void) {
 
 void rom_ext_main(void) {
   rom_ext_check_rom_expectations();
-  rom_ext_init();
+  SHUTDOWN_IF_ERROR(rom_ext_init());
   dbg_printf("Starting ROM_EXT\r\n");
   rom_error_t error = rom_ext_try_boot();
   // If the boot failed, enter bootstrap if it's enabled.

sw/device/silicon_creator/rom_ext/sival/BUILD

@@ -17,7 +17,7 @@ LINK_ORDER = [
     "$(location //sw/device/lib/crt)",
 ]
 
-manifest({
+manifest(d = {
     "name": "manifest_sival",
     "address_translation": hex(CONST.HARDENED_FALSE),
     "identifier": hex(CONST.ROM_EXT),