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- /*
- * 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.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
- #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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