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/*-
* Copyright (C) 2009-2011 Nathan Whitehorn
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/syscall.h>
#include <machine/trap.h>
#include <machine/param.h>
#include <machine/spr.h>
#include <machine/asm.h>
#define OFWSTKSZ 4096 /* 4K Open Firmware stack */
/*
* Globals
*/
.data
.align 4
ofwstk:
.space OFWSTKSZ
rtas_regsave:
.space 24 /* 3 * sizeof(register_t) */
GLOBAL(ofmsr)
.llong 0, 0, 0, 0, 0 /* msr/sprg0-3 used in Open Firmware */
GLOBAL(rtasmsr)
.llong 0
GLOBAL(openfirmware_entry)
.llong 0 /* Open Firmware entry point */
GLOBAL(rtas_entry)
.llong 0 /* RTAS entry point */
/*
* Open Firmware Real-mode Entry Point. This is a huge pain.
*/
ASENTRY_NOPROF(ofwcall)
mflr %r0
std %r0,16(%r1)
stdu %r1,-208(%r1)
/*
* We need to save the following, because OF's register save/
* restore code assumes that the contents of registers are
* at most 32 bits wide: lr, cr, r2, r13-r31, the old MSR. These
* get placed in that order in the stack.
*/
mfcr %r4
std %r4,48(%r1)
std %r13,56(%r1)
std %r14,64(%r1)
std %r15,72(%r1)
std %r16,80(%r1)
std %r17,88(%r1)
std %r18,96(%r1)
std %r19,104(%r1)
std %r20,112(%r1)
std %r21,120(%r1)
std %r22,128(%r1)
std %r23,136(%r1)
std %r24,144(%r1)
std %r25,152(%r1)
std %r26,160(%r1)
std %r27,168(%r1)
std %r28,176(%r1)
std %r29,184(%r1)
std %r30,192(%r1)
std %r31,200(%r1)
/* Record the old MSR */
mfmsr %r6
/* read client interface handler */
lis %r4,openfirmware_entry@ha
ld %r4,openfirmware_entry@l(%r4)
/*
* Set the MSR to the OF value. This has the side effect of disabling
* exceptions, which is important for the next few steps.
*/
lis %r5,ofmsr@ha
ld %r5,ofmsr@l(%r5)
mtmsrd %r5
isync
/*
* Set up OF stack. This needs to be accessible in real mode and
* use the 32-bit ABI stack frame format. The pointer to the current
* kernel stack is placed at the very top of the stack along with
* the old MSR so we can get them back later.
*/
mr %r5,%r1
lis %r1,(ofwstk+OFWSTKSZ-32)@ha
addi %r1,%r1,(ofwstk+OFWSTKSZ-32)@l
std %r5,8(%r1) /* Save real stack pointer */
std %r2,16(%r1) /* Save old TOC */
std %r6,24(%r1) /* Save old MSR */
li %r5,0
stw %r5,4(%r1)
stw %r5,0(%r1)
/* Finally, branch to OF */
mtctr %r4
bctrl
/* Reload stack pointer and MSR from the OFW stack */
ld %r6,24(%r1)
ld %r2,16(%r1)
ld %r1,8(%r1)
/* Now set the real MSR */
mtmsrd %r6
isync
/* Sign-extend the return value from OF */
extsw %r3,%r3
/* Restore all the non-volatile registers */
ld %r5,48(%r1)
mtcr %r5
ld %r13,56(%r1)
ld %r14,64(%r1)
ld %r15,72(%r1)
ld %r16,80(%r1)
ld %r17,88(%r1)
ld %r18,96(%r1)
ld %r19,104(%r1)
ld %r20,112(%r1)
ld %r21,120(%r1)
ld %r22,128(%r1)
ld %r23,136(%r1)
ld %r24,144(%r1)
ld %r25,152(%r1)
ld %r26,160(%r1)
ld %r27,168(%r1)
ld %r28,176(%r1)
ld %r29,184(%r1)
ld %r30,192(%r1)
ld %r31,200(%r1)
/* Restore the stack and link register */
ld %r1,0(%r1)
ld %r0,16(%r1)
mtlr %r0
blr
/*
* RTAS 32-bit Entry Point. Similar to the OF one, but simpler (no separate
* stack)
*
* C prototype: int rtascall(void *callbuffer, void *rtas_privdat);
*/
ASENTRY_NOPROF(rtascall)
mflr %r0
std %r0,16(%r1)
stdu %r1,-208(%r1)
/*
* We need to save the following, because RTAS's register save/
* restore code assumes that the contents of registers are
* at most 32 bits wide: lr, cr, r2, r13-r31, the old MSR. These
* get placed in that order in the stack.
*/
mfcr %r5
std %r5,48(%r1)
std %r13,56(%r1)
std %r14,64(%r1)
std %r15,72(%r1)
std %r16,80(%r1)
std %r17,88(%r1)
std %r18,96(%r1)
std %r19,104(%r1)
std %r20,112(%r1)
std %r21,120(%r1)
std %r22,128(%r1)
std %r23,136(%r1)
std %r24,144(%r1)
std %r25,152(%r1)
std %r26,160(%r1)
std %r27,168(%r1)
std %r28,176(%r1)
std %r29,184(%r1)
std %r30,192(%r1)
std %r31,200(%r1)
/* Record the old MSR */
mfmsr %r6
/* read client interface handler */
lis %r5,rtas_entry@ha
ld %r5,rtas_entry@l(%r5)
/*
* Set the MSR to the RTAS value. This has the side effect of disabling
* exceptions, which is important for the next few steps.
*/
lis %r7,rtasmsr@ha
ld %r7,rtasmsr@l(%r7)
mtmsrd %r7
isync
/*
* Set up RTAS register save area, so that we can get back all of
* our 64-bit pointers. Save our stack pointer, the TOC, and the MSR.
* Put this in r1, since RTAS is obliged to save it. Kernel globals
* are below 4 GB, so this is safe.
*/
mr %r7,%r1
lis %r1,rtas_regsave@ha
addi %r1,%r1,rtas_regsave@l
std %r7,0(%r1) /* Save 64-bit stack pointer */
std %r2,8(%r1) /* Save TOC */
std %r6,16(%r1) /* Save MSR */
/* Finally, branch to RTAS */
mtctr %r5
bctrl
/*
* Reload stack pointer and MSR from the reg save area in r1. We are
* running in 32-bit mode at this point, so it doesn't matter if r1
* has become sign-extended.
*/
ld %r6,16(%r1)
ld %r2,8(%r1)
ld %r1,0(%r1)
/* Now set the real MSR */
mtmsrd %r6
isync
/* Sign-extend the return value from RTAS */
extsw %r3,%r3
/* Restore all the non-volatile registers */
ld %r5,48(%r1)
mtcr %r5
ld %r13,56(%r1)
ld %r14,64(%r1)
ld %r15,72(%r1)
ld %r16,80(%r1)
ld %r17,88(%r1)
ld %r18,96(%r1)
ld %r19,104(%r1)
ld %r20,112(%r1)
ld %r21,120(%r1)
ld %r22,128(%r1)
ld %r23,136(%r1)
ld %r24,144(%r1)
ld %r25,152(%r1)
ld %r26,160(%r1)
ld %r27,168(%r1)
ld %r28,176(%r1)
ld %r29,184(%r1)
ld %r30,192(%r1)
ld %r31,200(%r1)
/* Restore the stack and link register */
ld %r1,0(%r1)
ld %r0,16(%r1)
mtlr %r0
blr
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