e141b62d20
When using QEMU PowerNV with latest op-build release (v2.7), its kexec transfers control to FreeBSD kernel in BE mode, causing an instant exception on LE kernels. Make kboot able to detect and swap endian to fix this. Reviewed by: imp Sponsored by: Instituto de Pesquisas Eldorado (eldorado.org.br) Differential Revision: https://reviews.freebsd.org/D33104
291 lines
6.9 KiB
ArmAsm
291 lines
6.9 KiB
ArmAsm
/* $FreeBSD$ */
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/*-
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* Copyright (C) 2010-2016 Nathan Whitehorn
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include "assym.inc"
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#include <sys/syscall.h>
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#include <machine/trap.h>
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#include <machine/param.h>
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#include <machine/spr.h>
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#include <machine/asm.h>
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#include <machine/vmparam.h>
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#ifdef _CALL_ELF
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.abiversion _CALL_ELF
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#endif
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/* Glue for linker script */
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.globl kernbase
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.set kernbase, KERNBASE
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/*
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* Globals
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*/
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.data
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.align 3
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GLOBAL(__startkernel)
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.llong begin
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GLOBAL(__endkernel)
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.llong end
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GLOBAL(can_wakeup)
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.llong 0x0
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.align 4
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#define TMPSTKSZ 16384 /* 16K temporary stack */
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GLOBAL(tmpstk)
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.space TMPSTKSZ
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TOC_ENTRY(tmpstk)
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TOC_ENTRY(can_wakeup)
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#ifdef KDB
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#define TRAPSTKSZ 8192 /* 8k trap stack */
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GLOBAL(trapstk)
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.space TRAPSTKSZ
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TOC_ENTRY(trapstk)
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#endif
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/*
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* Entry point for bootloaders that do not fully implement ELF and start
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* at the beginning of the image (kexec, notably). In its own section so
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* that it ends up before any linker-generated call stubs and actually at
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* the beginning of the image. kexec on some systems also enters at
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* (start of image) + 0x60, so put a spin loop there.
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*/
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.section ".text.kboot", "x", @progbits
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kbootentry:
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#ifdef __LITTLE_ENDIAN__
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RETURN_TO_NATIVE_ENDIAN
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#endif
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b __start
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. = kbootentry + 0x40 /* Magic address used in platform layer */
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.global smp_spin_sem
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ap_kexec_spin_sem:
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.long -1
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. = kbootentry + 0x60 /* Entry point for kexec APs */
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ap_kexec_start: /* At 0x60 past start, copied to 0x60 by kexec */
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/* r3 set to CPU ID by kexec */
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/* Invalidate icache for low-memory copy and jump there */
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li %r0,0x80
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dcbst 0,%r0
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sync
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icbi 0,%r0
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isync
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ba 0x80 /* Absolute branch to next inst */
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. = kbootentry + 0x80 /* Aligned to cache line */
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1: or 31,31,31 /* yield */
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sync
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lwz %r1,0x40(0) /* Spin on ap_kexec_spin_sem */
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cmpw %r1,%r3 /* Until it equals our CPU ID */
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bne 1b
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/* Released */
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or 2,2,2 /* unyield */
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/* Make sure that it will be software reset. Clear SRR1 */
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li %r1,0
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mtsrr1 %r1
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ba EXC_RST
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/*
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* Now start the real text section
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*/
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.text
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.globl btext
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btext:
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/*
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* Main kernel entry point.
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*
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* Calling convention:
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* r3: Flattened Device Tree pointer (or zero)
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* r4: ignored
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* r5: OF client interface pointer (or zero)
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* r6: Loader metadata pointer (or zero)
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* r7: Magic cookie (0xfb5d104d) to indicate that r6 has loader metadata
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*/
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.text
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_NAKED_ENTRY(__start)
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#ifdef __LITTLE_ENDIAN__
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RETURN_TO_NATIVE_ENDIAN
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#endif
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/* Set 64-bit mode if not yet set before branching to C */
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mfmsr %r20
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li %r21,1
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insrdi %r20,%r21,1,0
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mtmsrd %r20
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isync
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nop /* Make this block a multiple of 8 bytes */
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/* Set up the TOC pointer */
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b 0f
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.align 3
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0: nop
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bl 1f
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.llong __tocbase + 0x8000 - .
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1: mflr %r2
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ld %r1,0(%r2)
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add %r2,%r1,%r2
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/* Get load offset */
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ld %r31,-0x8000(%r2) /* First TOC entry is TOC base */
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subf %r31,%r31,%r2 /* Subtract from real TOC base to get base */
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/* Set up the stack pointer */
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bl 1f
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.llong tmpstk + TMPSTKSZ - 96 - .
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1: mflr %r30
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ld %r1,0(%r30)
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add %r1,%r1,%r30
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nop
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/* Relocate kernel */
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std %r3,48(%r1)
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std %r4,56(%r1)
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std %r5,64(%r1)
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std %r6,72(%r1)
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std %r7,80(%r1)
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bl 1f
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.llong _DYNAMIC-.
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1: mflr %r3
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ld %r4,0(%r3)
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add %r3,%r4,%r3
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mr %r4,%r31
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bl elf_reloc_self
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nop
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ld %r3,48(%r1)
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ld %r4,56(%r1)
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ld %r5,64(%r1)
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ld %r6,72(%r1)
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ld %r7,80(%r1)
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/* Begin CPU init */
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mr %r4,%r2 /* Replace ignored r4 with tocbase for trap handlers */
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bl powerpc_init
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nop
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/* Set stack pointer to new value and branch to mi_startup */
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mr %r1, %r3
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li %r3, 0
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std %r3, 0(%r1)
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bl mi_startup
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nop
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/* Unreachable */
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b .
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_END(__start)
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ASENTRY_NOPROF(__restartkernel_virtual)
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/*
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* When coming in via this entry point, we need to alter the SLB to
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* shadow the segment register emulation entries in DMAP space.
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* We need to do this dance because we are running with virtual-mode
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* OpenFirmware and have not yet taken over the MMU.
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*
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* Assumptions:
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* 1) The kernel is currently identity-mapped.
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* 2) We are currently executing at an address compatible with
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* real mode.
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* 3) The first 16 SLB entries are emulating SRs.
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* 4) The rest of the SLB is not in use.
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* 5) OpenFirmware is not manipulating the SLB at runtime.
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* 6) We are running on 64-bit AIM.
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*
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* Tested on a G5.
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*/
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mfmsr %r14
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/* Switch to real mode because we are about to mess with the SLB. */
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andi. %r14, %r14, ~(PSL_DR|PSL_IR|PSL_ME|PSL_RI)@l
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mtmsr %r14
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isync
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/* Prepare variables for later use. */
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li %r14, 0
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li %r18, 0
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oris %r18, %r18, 0xc000
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sldi %r18, %r18, 32 /* r18: 0xc000000000000000 */
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1:
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/*
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* Loop over the first 16 SLB entries.
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* Offset the SLBE into the DMAP, add 16 to the index, and write
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* it back to the SLB.
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*/
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/* XXX add more safety checks */
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slbmfev %r15, %r14
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slbmfee %r16, %r14
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or %r16, %r16, %r14 /* index is 0-15 */
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ori %r16, %r16, 0x10 /* add 16 to index. */
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or %r16, %r16, %r18 /* SLBE DMAP offset */
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rldicr %r17, %r16, 0, 37 /* Invalidation SLBE */
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isync
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slbie %r17
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/* isync */
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slbmte %r15, %r16
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isync
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addi %r14, %r14, 1
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cmpdi %r14, 16
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blt 1b
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/*
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* Now that we are set up with a temporary direct map, we can
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* continue with __restartkernel. Translation will be switched
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* back on at the rfid, at which point we will be executing from
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* the temporary direct map we just installed, until the kernel
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* takes over responsibility for the MMU.
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*/
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bl __restartkernel
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nop
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ASEND(__restartkernel_virtual)
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ASENTRY_NOPROF(__restartkernel)
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/*
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* r3-r7: arguments to go to __start
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* r8: offset from current kernel address to apply
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* r9: MSR to set when (atomically) jumping to __start + r8
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*/
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mtsrr1 %r9
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bl 1f
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1: mflr %r25
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add %r25,%r8,%r25
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addi %r25,%r25,2f-1b
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mtsrr0 %r25
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rfid
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2: bl __start
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nop
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ASEND(__restartkernel)
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#include <powerpc/aim/trap_subr64.S>
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