source: mainline/arch/sparc64/src/start.S@ 4037847

#
# Copyright (C) 2005 Jakub Jermar
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
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#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
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# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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#include <arch/boot/boot.h>

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

.section K_TEXT_START, "ax"

/*
 * Here is where the kernel is passed control.
 * The code must be position independent until
 * the kernel relocates itself to its VMA.
 */

.global kernel_image_start
kernel_image_start:
0:
        b 1f
        nop

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

.align 8

1:
        flushw                          ! flush all but the active register window

        /*
         * Prepare to copy the kernel image to 4M.
         */

        set LMA, %g1                    ! source address
        set VMA, %g2                    ! destination address
        set hardcoded_ktext_size, %g3   ! link address of hardcoded_ktext_size
        set hardcoded_kdata_size, %g4   ! link address of hardcoded_kdata_size

        sub %g3, %g2, %g3               ! offset of hardcoded_ktext_size from the beginning of the load address
        sub %g4, %g2, %g4               ! offset of hardcoded_kdata_size from the beginning of the load address
        
        ldx [%g3 + %g1], %g3            ! hardcoded_ktext_size -> %g3
        ldx [%g4 + %g1], %g4            ! hardcoded_kdata_size -> %g4

        add %g3, %g4, %g3               ! size of kernel text and data

        /*
         * Start copying the kernel from higher addresses towards lower addresses.
         */

2:      dec %g3
        ldub [%g1 + %g3], %g4
        stb %g4, [%g2 + %g3]
        cmp %g3, 0
        bnz 2b
        nop

        set relocated, %g1
        jmp %g1
        nop

relocated:
        set ofw, %l0

        call ofw_init
        stx %o4, [%l0]

        call ofw_init_memmap
        nop

        wrpr %r0, 0, %pil

        call main_bsp
        nop

        /* Not reached. */

2:
        b 2b
        nop