| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* PLT trampolines. Nios II version. |
| 2 | Copyright (C) 2005-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library. If not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <sysdep.h> |
| 20 | #include <libc-symbols.h> |
| 21 | |
| 22 | .text |
| 23 | .globl _dl_runtime_resolve |
| 24 | cfi_startproc |
| 25 | _dl_runtime_resolve: |
| 26 | /* The runtime resolver receives the original function arguments in r4 |
| 27 | through r7, the shared library identifier from GOT[1]? in r14, and the |
| 28 | relocation index times four in r15. It updates the corresponding PLT GOT |
| 29 | entry so that the PLT entry will transfer control directly to the target |
| 30 | in the future, and then transfers control to the target. */ |
| 31 | /* Save arguments and return address. */ |
| 32 | subi sp, sp, 28 |
| 33 | cfi_adjust_cfa_offset (28) |
| 34 | stw r22, 24(sp) |
| 35 | cfi_rel_offset (r22, 24) |
| 36 | stw r8, 20(sp) /* save r8, because this might be a call to mcount */ |
| 37 | cfi_rel_offset (r8, 20) |
| 38 | stw r7, 16(sp) |
| 39 | cfi_rel_offset (r7, 16) |
| 40 | stw r6, 12(sp) |
| 41 | cfi_rel_offset (r6, 12) |
| 42 | stw r5, 8(sp) |
| 43 | cfi_rel_offset (r5, 8) |
| 44 | stw r4, 4(sp) |
| 45 | cfi_rel_offset (r4, 4) |
| 46 | stw ra, 0(sp) |
| 47 | cfi_rel_offset (ra, 0) |
| 48 | |
| 49 | /* Get pointer to linker struct. */ |
| 50 | mov r4, r14 |
| 51 | |
| 52 | /* Get the relocation offset. We're given a multiple of 4 and |
| 53 | need a multiple of 12, so multiply by 3. */ |
| 54 | slli r5, r15, 1 |
| 55 | add r5, r5, r15 |
| 56 | |
| 57 | /* Call the fixup routine. */ |
| 58 | nextpc r22 |
| 59 | 1: movhi r2, %hiadj(_gp_got - 1b) |
| 60 | addi r2, r2, %lo(_gp_got - 1b) |
| 61 | add r22, r22, r2 |
| 62 | ldw r2, %call(_dl_fixup)(r22) |
| 63 | callr r2 |
| 64 | |
| 65 | /* Restore the arguments and return address. */ |
| 66 | ldw ra, 0(sp) |
| 67 | ldw r4, 4(sp) |
| 68 | ldw r5, 8(sp) |
| 69 | ldw r6, 12(sp) |
| 70 | ldw r7, 16(sp) |
| 71 | ldw r8, 20(sp) |
| 72 | ldw r22, 24(sp) |
| 73 | addi sp, sp, 28 |
| 74 | cfi_adjust_cfa_offset (-28) |
| 75 | |
| 76 | /* Jump to the newly found address. */ |
| 77 | jmp r2 |
| 78 | |
| 79 | cfi_endproc |