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-rw-r--r--src/sys/kernel.S19
1 files changed, 15 insertions, 4 deletions
diff --git a/src/sys/kernel.S b/src/sys/kernel.S
index cee385d..4a3c096 100644
--- a/src/sys/kernel.S
+++ b/src/sys/kernel.S
@@ -3,15 +3,26 @@
.globl kernel_main
kernel_main:
bl sysinit
-kernel_main.loop:
+ cps #0x10
+ // Intentional undefined instruction
+ .word 0xf7f0a000
+ // Supervisor Call #1 - Does nothing special
+ svc #1
+ mrs r0, cpsr
+ bl uart_hexn
+ // Supervisor Call #1 - Returns in supervisor mode
+ svc #0
+ mrs r0, cpsr
+ bl uart_hexn
+1:
//bl schedule
wfe
- b kernel_main.loop
+ b 1b
.section ".data"
.globl cntfrq
-cntfrq:
- .word 0,0,0,0
+cntfrq: // 32 bits
+ .word 0
.globl cmdidx
cmdidx:
.word 0