/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* crt0_r.S: Entry function for SPU-side context restore.
*
* Copyright (C) 2005 IBM
*
* Entry and exit function for SPU-side of the context restore
* sequence. Sets up an initial stack frame, then branches to
* 'main'. On return, restores all 128 registers from the LSCSA
* and exits.
*/
#include <asm/spu_csa.h>
.data
.align 7
.globl regs_spill
regs_spill:
.space SIZEOF_SPU_SPILL_REGS, 0x0
.text
.global _start
_start:
/* 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
.global exit
.global _exit
exit:
_exit:
/* SPU Context Restore, Step 5: Restore the remaining 112 GPRs. */
ila $3, regs_spill + 256
restore_regs:
lqr $4, restore_reg_insts
restore_reg_loop:
ai $4, $4, 4
.balignl 16, 0x40200000
restore_reg_insts: /* must be quad-word aligned. */
lqd $16, 0($3)
lqd $17, 16($3)
lqd $18, 32($3)
lqd $19, 48($3)
andi $5, $4, 0x7F
stqr $4, restore_reg_insts
ai $3, $3, 64
brnz $5, restore_reg_loop
/* SPU Context Restore Step 17: Restore the first 16 GPRs. */
lqa $0, regs_spill + 0
lqa $1, regs_spill + 16
lqa $2, regs_spill + 32
lqa $3, regs_spill + 48
lqa $4, regs_spill + 64
lqa $5, regs_spill + 80
lqa $6, regs_spill + 96
lqa $7, regs_spill + 112
lqa $8, regs_spill + 128
lqa $9, regs_spill + 144
lqa $10, regs_spill + 160
lqa $11, regs_spill + 176
lqa $12, regs_spill + 192
lqa $13, regs_spill + 208
lqa $14, regs_spill + 224
lqa $15, regs_spill + 240
/* Under normal circumstances, the 'exit' function
* terminates with 'stop SPU_RESTORE_COMPLETE',
* indicating that the SPU-side restore code has
* completed.
*
* However it is possible that instructions immediately
* following the 'stop 0x3ffc' have been modified at run
* time so as to recreate the exact SPU_Status settings
* from the application, e.g. illegal instruciton, halt,
* etc.
*/
.global exit_fini
.global _exit_fini
exit_fini:
_exit_fini:
stop SPU_RESTORE_COMPLETE
stop 0
stop 0
stop 0
/* Pad the size of this crt0.o to be multiple of 16 bytes. */
.balignl 16, 0x0
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