felboot: Prevent GCC from reordering _start. Must be at a known address

felboot/fel-boot.ld

@@ -7,7 +7,7 @@ SECTIONS
  . = ALIGN(4);
  .text :
  {
-  main.o (.text*)
+  main.o (.text.start)
   *(.text*)
  }
  . = ALIGN(4);

felboot/main.c

@@ -19,7 +19,7 @@
 
 #include <stdio.h>
 
-void _start(void)
+__attribute__ ((section (".text.start"))) void _start(void)
 {
 	clock_init();
 	gpio_init();