From a92d45c3df893c845571506afe6fbbfb3e7a85aa Mon Sep 17 00:00:00 2001
From: Damien George <damien@micropython.org>
Date: Thu, 17 Mar 2022 17:11:03 +1100
Subject: [PATCH] stm32/mboot: Always check the magic number to enter
 filesystem loading.

Even if MBOOT_FSLOAD is disabled, mboot should still check for 0x70ad0080
so it can immediately return to the application if this feature is not
enabled.  Otherwise mboot will get stuck in DFU mode.

Signed-off-by: Damien George <damien@micropython.org>
---
 ports/stm32/mboot/main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ports/stm32/mboot/main.c b/ports/stm32/mboot/main.c
index ac564d1d06..341cf18179 100644
--- a/ports/stm32/mboot/main.c
+++ b/ports/stm32/mboot/main.c
@@ -1539,8 +1539,8 @@ enter_bootloader:
     mboot_pack_init();
     #endif
 
-    #if MBOOT_FSLOAD
     if ((initial_r0 & 0xffffff80) == 0x70ad0080) {
+        #if MBOOT_FSLOAD
         // Application passed through elements, validate then process them
         const uint8_t *elem_end = elem_search(ELEM_DATA_START, ELEM_TYPE_END);
         if (elem_end != NULL && elem_end[-1] == 0) {
@@ -1553,11 +1553,11 @@ enter_bootloader:
                 *status_ptr = ret;
             }
         }
+        #endif
         // Always reset because the application is expecting to resume
         led_state_all(0);
         leave_bootloader();
     }
-    #endif
 
     dfu_init();