/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * crt0_s.S: Entry function for SPU-side context save.
 *
 * Copyright (C) 2005 IBM
 *
 * Entry function for SPU-side of the context save sequence.
 * Saves all 128 GPRs, sets up an initial stack frame, then
 * branches to 'main'.
 */

#include <asm/spu_csa.h>

.data
.align 7
.globl regs_spill
regs_spill:
.space SIZEOF_SPU_SPILL_REGS, 0x0

.text
.global _start
_start:
        /* SPU Context Save Step 1: Save the first 16 GPRs. */
        stqa $0, regs_spill + 0
        stqa $1, regs_spill + 16
        stqa $2, regs_spill + 32
        stqa $3, regs_spill + 48
        stqa $4, regs_spill + 64
        stqa $5, regs_spill + 80
        stqa $6, regs_spill + 96
        stqa $7, regs_spill + 112
        stqa $8, regs_spill + 128
        stqa $9, regs_spill + 144
        stqa $10, regs_spill + 160
        stqa $11, regs_spill + 176
        stqa $12, regs_spill + 192
        stqa $13, regs_spill + 208
        stqa $14, regs_spill + 224
        stqa $15, regs_spill + 240

        /* SPU Context Save, Step 8: Save the remaining 112 GPRs. */
        ila     $3, regs_spill + 256
save_regs:
        lqr     $4, save_reg_insts
save_reg_loop:
        ai      $4, $4, 4
        .balignl 16, 0x40200000
save_reg_insts:       /* must be quad-word aligned. */
        stqd    $16, 0($3)
        stqd    $17, 16($3)
        stqd    $18, 32($3)
        stqd    $19, 48($3)
        andi    $5, $4, 0x7F
        stqr    $4, save_reg_insts
        ai      $3, $3, 64
        brnz    $5, save_reg_loop

        /* Initialize the stack pointer to point to 16368
         * (16kb-16). The back chain pointer is initialized
         * to NULL.
         */
        il      $0, 0
        il      $SP, 16368
        stqd    $0, 0($SP)

        /* Allocate a minimum stack frame for the called main.
         * This is needed so that main has a place to save the
         * link register when it calls another function.
         */
        stqd    $SP, -160($SP)
        ai      $SP, $SP, -160

        /* Call the program's main function. */
        brsl    $0, main

        /* In this case main should not return; if it does
         * there has been an error in the sequence.  Execute
         * stop-and-signal with code=0.
         */
.global exit
.global _exit
exit:
_exit:
        stop    0x0

        /* Pad the size of this crt0.o to be multiple of 16 bytes. */
.balignl 16, 0x0