source: mainline/boot/arch/sparc64/src/asm.S@ 339249f

#
# Copyright (c) 2006 Martin Decky
# Copyright (c) 2006 Jakub Jermar
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - 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.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# 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 THE AUTHOR 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.
#

#include <arch/arch.h>

#define ICACHE_SIZE       8192
#define ICACHE_LINE_SIZE  32
#define ICACHE_SET_BIT    (1 << 13)
#define ASI_ICACHE_TAG    0x67

.register %g2, #scratch
.register %g3, #scratch
.register %g6, #scratch
.register %g7, #scratch

.global start
.global halt
.global memcpy
.global jump_to_kernel

.section BOOTSTRAP, "ax"

start:
        ba %xcc, 1f
        nop

/*
 * This header forces SILO to load the image at 0x4000.
 * More precisely, SILO will think this is an old version of Linux.
 */
.ascii "HdrS"
.word 0
.half 0
.half 0
.half 0
.half 0
.word 0
.word 0

.align 8
1:
        ! Disable interrupts and disable address masking.
        
        wrpr %g0, PSTATE_PRIV_BIT, %pstate
        
        wrpr %g0, NWINDOWS - 2, %cansave   ! Set maximum saveable windows
        wrpr %g0, 0, %canrestore           ! Get rid of windows we will never need again
        wrpr %g0, 0, %otherwin             ! Make sure the window state is consistent
        wrpr %g0, NWINDOWS - 1, %cleanwin  ! Prevent needless clean_window traps for kernel
        
        set initial_stack, %sp
        add %sp, -STACK_BIAS, %sp
        
        set ofw_cif, %l0
        
        ! Initialize OpenFirmware
        
        call ofw_init
        stx %o4, [%l0]
        
        ba %xcc, bootstrap
        nop

.align STACK_ALIGNMENT
        .space STACK_SIZE
initial_stack:
        .space STACK_WINDOW_SAVE_AREA_SIZE

.text

halt:
        ba %xcc, halt
        nop

memcpy:
        ! Save dst
        
        mov %o0, %o3
        add %o1, 7, %g1
        and %g1, -8, %g1
        cmp %o1, %g1
        be,pn %xcc, 3f
        add %o0, 7, %g1
        mov 0, %g3
        
        0:
                brz,pn %o2, 2f
                mov 0, %g2
        
        1:
                ldub [%g3 + %o1], %g1
                add %g2, 1, %g2
                cmp %o2, %g2
                stb %g1, [%g3 + %o0]
                bne,pt %xcc, 1b
                mov %g2, %g3
        
        2:
                ! Exit point
                
                jmp %o7 + 8
                mov %o3, %o0
        
        3:
                and %g1, -8, %g1
                cmp %o0, %g1
                bne,pt %xcc, 0b
                mov 0, %g3
                srlx %o2, 3, %g4
                brz,pn %g4, 5f
                mov 0, %g5
        
        4:
                sllx %g3, 3, %g2
                add %g5, 1, %g3
                ldx [%o1 + %g2], %g1
                mov %g3, %g5
                cmp %g4, %g3
                bne,pt %xcc, 4b
                stx %g1, [%o0 + %g2]
        
        5:
                and %o2, 7, %o2
                brz,pn %o2, 2b
                sllx %g4, 3, %g1
                mov 0, %g2
                add %g1, %o0, %o0
                add %g1, %o1, %g4
                mov 0, %g3
        
        6:
                ldub [%g2 + %g4], %g1
                stb %g1, [%g2 + %o0]
                add %g3, 1, %g2
                cmp %o2, %g2
                bne,pt %xcc, 6b
                mov %g2, %g3
        
        ! Exit point
        
        jmp %o7 + 8
        mov %o3, %o0

jump_to_kernel:
        /*
         * Guarantee cache coherence:
         * 1. Make sure that the code we have moved has drained to main memory.
         * 2. Invalidate I-cache.
         * 3. Flush instruction pipeline.
         */
        
        /*
         * US3 processors have a write-invalidate cache, so explicitly
         * invalidating it is not required. Whether to invalidate I-cache
         * or not is decided according to the value of the 3rd argument
         * (subarch).
         */
        cmp %o2, SUBARCH_US3
        be %xcc, 1f
        nop
        
        0:
                call icache_flush
                nop
        
        1:
                membar #StoreStore
        
        /*
         * Flush the instruction pipeline.
         */
        flush %i7
        
        ! Jump to kernel
        jmp %o3
        nop

# Flush I-cache
icache_flush:
        set ((ICACHE_SIZE - ICACHE_LINE_SIZE) | ICACHE_SET_BIT), %g1
        stxa %g0, [%g1] ASI_ICACHE_TAG
        
        0:
                membar #Sync
                subcc %g1, ICACHE_LINE_SIZE, %g1
                bnz,pt %xcc, 0b
        
        stxa %g0, [%g1] ASI_ICACHE_TAG
        membar #Sync
        retl
        
        ! SF Erratum #51
        
        nop

.global ofw
ofw:
        save %sp, -STACK_WINDOW_SAVE_AREA_SIZE, %sp
        set ofw_cif, %l0
        ldx [%l0], %l0
        
        rdpr %pstate, %l1
        and %l1, ~PSTATE_AM_BIT, %l2
        wrpr %l2, 0, %pstate
        
        jmpl %l0, %o7
        mov %i0, %o0
        
        wrpr %l1, 0, %pstate
        
        ret
        restore %o0, 0, %o0