projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 63d143a2 CM |
1 | /* Copyright (C) 2011 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. | |
| 3 | Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011. | |
| 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, write to the Free | |
| 17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
| 18 | 02111-1307 USA. */ | |
| 19 | ||
| 20 | #include <sysdep.h> | |
| 21 | ||
| 22 | /* Get address of "sym" in "reg" assuming r51 holds ".Llink". */ | |
| 23 | .macro pic_addr reg, sym | |
| 24 | #ifdef __tilegx__ | |
| 25 | moveli \reg, hw1_last(\sym - .Llink) | |
| 26 | shl16insli \reg, \reg, hw0(\sym - .Llink) | |
| 27 | ADD_PTR \reg, r51, \reg | |
| 28 | #else | |
| 29 | ADDLI_PTR \reg, r51, lo16(\sym - .Llink) | |
| 30 | auli \reg, \reg, ha16(\sym - .Llink) | |
| 31 | #endif | |
| 32 | .endm | |
| 33 | ||
| 34 | .text | |
| 35 | ENTRY (_start) | |
| 36 | /* Linux starts us with sp pointing at the conventional Elf layout, | |
| 37 | but we need to allow two 'caller' words for our ABI convention. */ | |
| 38 | { | |
| 39 | move r52, sp | |
| 40 | andi sp, sp, -8 | |
| 41 | } | |
| 42 | cfi_def_cfa_register (r52) | |
| 43 | { | |
| 44 | /* Point sp at base of ABI area; point r4 to the caller-sp word. */ | |
| 45 | ADDI_PTR sp, sp, -(2 * REGSIZE) | |
| 46 | ADDI_PTR r4, sp, -REGSIZE | |
| 47 | } | |
| 48 | { | |
| 49 | /* Save zero for caller sp in our 'caller' save area, and make | |
| 50 | sure lr has a zero value, to limit backtraces. */ | |
| 51 | move lr, zero | |
| 52 | ST r4, zero | |
| 53 | } | |
| 54 | { | |
| 55 | move r0, r52 | |
| 56 | jal _dl_start | |
| 57 | } | |
| 58 | /* Save returned start of user program address for later. */ | |
| 59 | move r50, r0 | |
| 60 | ||
| 61 | /* See if we were invoked explicitly with the dynamic loader, | |
| 62 | in which case we have to adjust the argument vector. */ | |
| 63 | lnk r51; .Llink: | |
| 64 | pic_addr r4, _dl_skip_args | |
| 65 | LD4U r4, r4 | |
| 66 | BEQZT r4, .Lno_skip | |
| 67 | ||
| 68 | /* Load the argc word at the initial sp and adjust it. | |
| 69 | We basically jump "sp" up over the first few argv entries | |
| 70 | and write "argc" a little higher up in memory, to be the | |
| 71 | base of the new kernel-initialized stack area. */ | |
| 72 | LD_PTR r0, r52 | |
| 73 | { | |
| 74 | sub r0, r0, r4 | |
| 75 | SHL_PTR_ADD r52, r4, r52 | |
| 76 | } | |
| 77 | { | |
| 78 | ST_PTR r52, r0 | |
| 79 | SHL_PTR_ADD sp, r4, sp | |
| 80 | } | |
| 81 | ||
| 82 | .Lno_skip: | |
| 83 | /* Call_dl_init (_dl_loaded, argc, argv, envp). See elf/start.s | |
| 84 | for the layout of memory here; r52 is pointing to "+0". */ | |
| 85 | pic_addr r0, _rtld_local | |
| 86 | { | |
| 87 | LD_PTR r1, r52 /* load argc in r1 */ | |
| 88 | ADDLI_PTR r2, r52, __SIZEOF_POINTER__ /* point r2 at argv */ | |
| 89 | } | |
| 90 | { | |
| 91 | LD_PTR r0, r0 /* yields _rtld_global._ns_loaded */ | |
| 92 | addi r3, r1, 1 | |
| 93 | move lr, zero | |
| 94 | } | |
| 95 | { | |
| 96 | SHL_PTR_ADD r3, r3, r2 /* point r3 at envp */ | |
| 97 | jal _dl_init_internal | |
| 98 | } | |
| 99 | ||
| 100 | /* Call user program whose address we saved in r50. | |
| 101 | We invoke it just like a static binary, but with _dl_fini | |
| 102 | in r0 so we can distinguish. */ | |
| 103 | ||
| 104 | pic_addr r0, _dl_fini | |
| 105 | move lr, zero | |
| 106 | { | |
| 107 | move sp, r52 | |
| 108 | jr r50 | |
| 109 | } | |
| 110 | ||
| 111 | /* Tell backtracer to give up (_start has no caller). */ | |
| 112 | info 2 /* INFO_OP_CANNOT_BACKTRACE */ | |
| 113 | ||
| 114 | END (_start) |