[rom_ext] Clear power-on-reset in self-requested reboots

Signed-off-by: Chris Frantz <[email protected]>
(cherry picked from commit 4295c6f)

Author: cfrantz

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

@@ -168,3 +168,8 @@ bool rstmgr_is_hw_reset_reason(dt_rstmgr_t dt, uint32_t reasons,
 
   return false;
 }
+
+void rstmgr_reboot(void) {
+  rstmgr_reason_clear(1 << kRstmgrReasonPowerOn);
+  rstmgr_reset();
+}

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

@@ -115,6 +115,18 @@ noreturn
     void
     rstmgr_reset(void);
 
+/**
+ * Reboot the chip.
+ *
+ * This function clears the power-on-reset reason and then resets the chip.
+ */
+#ifdef OT_PLATFORM_RV32
+// Omit `noreturn` to be able to test this function in off-target tests.
+noreturn
+#endif
+    void
+    rstmgr_reboot(void);
+
 /**
  * Verifies that info collection is initialized properly.
  *

sw/device/silicon_creator/lib/rescue/dfu.c

@@ -318,7 +318,7 @@ void dfu_protocol_handler(void *_ctx, uint8_t ep, usb_transfer_flags_t flags,
   if (flags & kUsbTransferFlagsReset) {
     // A USB reset after we've been enumerated means software reset.
     if (ctx->ep0.device_address && ctx->ep0.configuration) {
-      rstmgr_reset();
+      rstmgr_reboot();
     }
   }
 

sw/device/silicon_creator/lib/rescue/rescue_spi.c

@@ -130,7 +130,7 @@ rom_error_t rescue_protocol(boot_data_t *bootdata, boot_log_t *boot_log,
       } break;
 
       case kSpiDeviceOpcodeReset:
-        rstmgr_reset();
+        rstmgr_reboot();
         break;
       default:
         dfu_transport_result(&ctx, kErrorUsbBadSetup);

sw/device/silicon_creator/lib/rescue/rescue_xmodem.c

@@ -156,7 +156,7 @@ rom_error_t rescue_protocol(boot_data_t *bootdata, boot_log_t *boot_log,
   rescue_state_init(&rescue_state, bootdata, boot_log, config);
   rom_error_t result = protocol(&rescue_state);
   if (result == kErrorRescueReboot) {
-    rstmgr_reset();
+    rstmgr_reboot();
   }
   return result;
 }

sw/device/silicon_creator/rom_ext/rom_ext.c

@@ -767,7 +767,7 @@ static rom_error_t rom_ext_start(boot_data_t *boot_data, boot_log_t *boot_log) {
     if (error == kErrorRescueInactivity &&
         boot_attempted == kHardenedBoolFalse) {
       rescue_skip_next_boot();
-      rstmgr_reset();
+      rstmgr_reboot();
     }
   }