linux/arch/powerpc/boot/opal-calls.S
Oliver O'Halloran 656ad58ef1 powerpc/boot: Add OPAL console to epapr wrappers
This patch adds an OPAL console backend to the powerpc boot wrapper so
that decompression failures inside the wrapper can be reported to the
user. This is important since it typically indicates data corruption in
the firmware and other nasty things.

Currently this only works when building a little endian kernel. When
compiling a 64 bit BE kernel the wrapper is always build 32 bit to be
compatible with some 32 bit firmwares. BE support will be added at a
later date. Another limitation of this is that only the "raw" type of
OPAL console is supported, however machines that provide a hvsi console
also provide a raw console so this is not an issue in practice.

Actually-written-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Move #ifdef __powerpc64__ to avoid warnings on 32-bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 23:58:54 +10:00

59 lines
1.2 KiB
ArmAsm

/*
* Copyright (c) 2016 IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include "ppc_asm.h"
#include "../include/asm/opal-api.h"
.text
#define OPAL_CALL(name, token) \
.globl name; \
name: \
li r0, token; \
b opal_call;
opal_call:
mflr r11
std r11,16(r1)
mfcr r12
stw r12,8(r1)
mr r13,r2
/* Set opal return address */
ld r11,opal_return@got(r2)
mtlr r11
mfmsr r12
/* switch to BE when we enter OPAL */
li r11,MSR_LE
andc r12,r12,r11
mtspr SPRN_HSRR1,r12
/* load the opal call entry point and base */
ld r11,opal@got(r2)
ld r12,8(r11)
ld r2,0(r11)
mtspr SPRN_HSRR0,r12
hrfid
opal_return:
FIXUP_ENDIAN
mr r2,r13;
lwz r11,8(r1);
ld r12,16(r1)
mtcr r11;
mtlr r12
blr
OPAL_CALL(opal_console_write, OPAL_CONSOLE_WRITE);
OPAL_CALL(opal_console_read, OPAL_CONSOLE_READ);
OPAL_CALL(opal_console_write_buffer_space, OPAL_CONSOLE_WRITE_BUFFER_SPACE);
OPAL_CALL(opal_poll_events, OPAL_POLL_EVENTS);
OPAL_CALL(opal_console_flush, OPAL_CONSOLE_FLUSH);