serial port works, added setup instructions

[rpikern] / src / startup.s

diff --git a/src/startup.s b/src/startup.s
index d0b402f..7765ede 100644 (file)
--- a/src/startup.s
+++ b/src/startup.s
@@ -4,10 +4,13 @@
        .code 32
 
 startup:
-       ldr sp, =_stacktop
+       @ stop all but one of the cores
+       mrc p15, 0, r0, c0, c0, 5
+       ands r0, r0, #0xff
+       bne exit
 
-       mov r0, #2
-       bl dbgled
+       @ setup stack
+       ldr sp, =_stacktop
 
        @ clear bss
        ldr r0, =_bss_start
@@ -19,10 +22,7 @@ startup:
        subs r1, #4
        bne 0b
 1:
-       bl main
-
-       mov r0, #0
-       bl dbgled
+       blx main
 
        .global exit
 exit:  wfe