root/arch/powerpc/boot/ps3-head.S
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  PS3 bootwrapper entry.
 *
 *  Copyright (C) 2007 Sony Computer Entertainment Inc.
 *  Copyright 2007 Sony Corp.
 */

#include "ppc_asm.h"

        .machine "ppc64"

        .text

/*
 * __system_reset_overlay - The PS3 first stage entry.
 *
 * The bootwraper build script copies the 512 bytes at symbol
 * __system_reset_overlay to offset 0x100 of the rom image.  This symbol
 * must occupy 512 or less bytes.
 *
 * The PS3 has a single processor with two threads.
 */

        .globl __system_reset_overlay
__system_reset_overlay:

        /* Switch to 32-bit mode. */

        mfmsr   r9
        clrldi  r9,r9,1
        mtmsrd  r9
        nop

        /* Get thread number in r3 and branch. */

        mfspr   r3, 0x88
        cntlzw. r3, r3
        beq     1f

        /* Secondary goes to __secondary_hold in kernel. */

        li      r4, 0x60
        mtctr   r4
        bctr

1:
        /* Primary delays then goes to _zimage_start in wrapper. */

        or      31, 31, 31 /* db16cyc */
        or      31, 31, 31 /* db16cyc */

        lis     r4, _zimage_start@ha
        addi    r4, r4, _zimage_start@l
        mtctr   r4
        bctr

        . = __system_reset_overlay + 512

/*
 * __system_reset_kernel - Place holder for the kernel reset vector.
 *
 * The bootwrapper build script copies 512 bytes from offset 0x100
 * of the rom image to the symbol __system_reset_kernel.  At runtime
 * the bootwrapper program copies the 512 bytes at __system_reset_kernel
 * to ram address 0x100.  This symbol must occupy 512 bytes.
 */

        .globl __system_reset_kernel
__system_reset_kernel:

        . = __system_reset_kernel + 512