| Mark Nutter | 05b8411 | 2005-11-15 15:53:51 -0500 | [diff] [blame^] | 1 | /* |
| 2 | * crt0_r.S: Entry function for SPU-side context restore. |
| 3 | * |
| 4 | * Copyright (C) 2005 IBM |
| 5 | * |
| 6 | * Entry and exit function for SPU-side of the context restore |
| 7 | * sequence. Sets up an initial stack frame, then branches to |
| 8 | * 'main'. On return, restores all 128 registers from the LSCSA |
| 9 | * and exits. |
| 10 | * |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2, or (at your option) |
| 15 | * any later version. |
| 16 | * |
| 17 | * This program is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with this program; if not, write to the Free Software |
| 24 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 25 | */ |
| 26 | |
| 27 | #include <asm/spu_csa.h> |
| 28 | |
| 29 | .data |
| 30 | .align 7 |
| 31 | .globl regs_spill |
| 32 | regs_spill: |
| 33 | .space SIZEOF_SPU_SPILL_REGS, 0x0 |
| 34 | |
| 35 | .text |
| 36 | .global _start |
| 37 | _start: |
| 38 | /* Initialize the stack pointer to point to 16368 |
| 39 | * (16kb-16). The back chain pointer is initialized |
| 40 | * to NULL. |
| 41 | */ |
| 42 | il $0, 0 |
| 43 | il $SP, 16368 |
| 44 | stqd $0, 0($SP) |
| 45 | |
| 46 | /* Allocate a minimum stack frame for the called main. |
| 47 | * This is needed so that main has a place to save the |
| 48 | * link register when it calls another function. |
| 49 | */ |
| 50 | stqd $SP, -160($SP) |
| 51 | ai $SP, $SP, -160 |
| 52 | |
| 53 | /* Call the program's main function. */ |
| 54 | brsl $0, main |
| 55 | |
| 56 | .global exit |
| 57 | .global _exit |
| 58 | exit: |
| 59 | _exit: |
| 60 | /* SPU Context Restore, Step 5: Restore the remaining 112 GPRs. */ |
| 61 | ila $3, regs_spill + 256 |
| 62 | restore_regs: |
| 63 | lqr $4, restore_reg_insts |
| 64 | restore_reg_loop: |
| 65 | ai $4, $4, 4 |
| 66 | .balignl 16, 0x40200000 |
| 67 | restore_reg_insts: /* must be quad-word aligned. */ |
| 68 | lqd $16, 0($3) |
| 69 | lqd $17, 16($3) |
| 70 | lqd $18, 32($3) |
| 71 | lqd $19, 48($3) |
| 72 | andi $5, $4, 0x7F |
| 73 | stqr $4, restore_reg_insts |
| 74 | ai $3, $3, 64 |
| 75 | brnz $5, restore_reg_loop |
| 76 | |
| 77 | /* SPU Context Restore Step 17: Restore the first 16 GPRs. */ |
| 78 | lqa $0, regs_spill + 0 |
| 79 | lqa $1, regs_spill + 16 |
| 80 | lqa $2, regs_spill + 32 |
| 81 | lqa $3, regs_spill + 48 |
| 82 | lqa $4, regs_spill + 64 |
| 83 | lqa $5, regs_spill + 80 |
| 84 | lqa $6, regs_spill + 96 |
| 85 | lqa $7, regs_spill + 112 |
| 86 | lqa $8, regs_spill + 128 |
| 87 | lqa $9, regs_spill + 144 |
| 88 | lqa $10, regs_spill + 160 |
| 89 | lqa $11, regs_spill + 176 |
| 90 | lqa $12, regs_spill + 192 |
| 91 | lqa $13, regs_spill + 208 |
| 92 | lqa $14, regs_spill + 224 |
| 93 | lqa $15, regs_spill + 240 |
| 94 | |
| 95 | /* Under normal circumstances, the 'exit' function |
| 96 | * terminates with 'stop SPU_RESTORE_COMPLETE', |
| 97 | * indicating that the SPU-side restore code has |
| 98 | * completed. |
| 99 | * |
| 100 | * However it is possible that instructions immediately |
| 101 | * following the 'stop 0x3ffc' have been modified at run |
| 102 | * time so as to recreate the exact SPU_Status settings |
| 103 | * from the application, e.g. illegal instruciton, halt, |
| 104 | * etc. |
| 105 | */ |
| 106 | .global exit_fini |
| 107 | .global _exit_fini |
| 108 | exit_fini: |
| 109 | _exit_fini: |
| 110 | stop SPU_RESTORE_COMPLETE |
| 111 | stop 0 |
| 112 | stop 0 |
| 113 | stop 0 |
| 114 | |
| 115 | /* Pad the size of this crt0.o to be multiple of 16 bytes. */ |
| 116 | .balignl 16, 0x0 |