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// SPDX-License-Identifier: Apache-2.0
/*
* hello_kernel.S!
*
* Because skiboot has its own stack, we don't even need that!
* All we need to do is make an OPAL call to write to the console.
*
* Copyright 2014-2016 IBM Corp.
*/
. = 0x0
.globl _start
_start:
/*
* Save some values passed in from skiboot into registers that are
* non-volatile over OPAL calls.
* r8 is the OPAL base
* r9 is the OPAL entry point point
*/
mr %r13, %r8
mr %r14, %r9
bl here
here: mflr %r8 /* work out where we are running */
li %r0, 1 /* OPAL_CONSOLE_WRITE */
li %r3, 0 /* terminal 0 */
addi %r4, %r8, len - here /* ptr to length of string */
addi %r5, %r8, str - here /* ptr to string start */
mr %r2, %r13
mtctr %r14
bctrl
li %r0, 5 /* OPAL_CEC_POWER_DOWN */
li %r3, 0 /* normal shutdown */
mr %r2, %r13
mtctr %r14
bctrl
/* We shouldn't get here but if we do, just wait here */
b .
len:
.long 0x00
.long (strend - str)
str:
.string "Hello World!\n"
strend:
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