diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/sys/kernel.S | 19 |
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 |