diff --git a/src/bootldr/fileops.h b/src/bootldr/fileops.h
index 8f55a70..922da27 100644
--- a/src/bootldr/fileops.h
+++ b/src/bootldr/fileops.h
@@ -31,7 +31,7 @@
 
 enum filestates { FILE_OK=0, FILE_ERR, FILE_EOF };
 
-BYTE file_buf[512];
+BYTE file_buf[512] __attribute__((aligned(4)));
 FATFS fatfs;
 FIL file_handle;
 FRESULT file_res;
diff --git a/src/bootldr/iap.c b/src/bootldr/iap.c
index 34dbb1d..c9c476d 100644
--- a/src/bootldr/iap.c
+++ b/src/bootldr/iap.c
@@ -189,7 +189,7 @@ FLASH_RES flash_file(uint8_t *filename) {
       }
       DBG_UART uart_putc('w');
       if((res = iap_ram2flash(flash_addr, file_buf, 512)) != CMD_SUCCESS) {
-        DBG_BL printf("error %ld while writing to address %08lx (sector %d)\n", res, flash_addr, current_sec);
+        DBG_BL printf("error %ld while writing from %08lX to address %08lx (sector %d)\n", res, (uint32_t)file_buf, flash_addr, current_sec);
         DBG_UART uart_putc('X');
         return ERR_FLASH;
       }