diff options
Diffstat (limited to 'REORG.TODO/sysdeps/s390/s390-64/start.S')
| -rw-r--r-- | REORG.TODO/sysdeps/s390/s390-64/start.S | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/s390/s390-64/start.S b/REORG.TODO/sysdeps/s390/s390-64/start.S new file mode 100644 index 0000000000..d8e65450d8 --- /dev/null +++ b/REORG.TODO/sysdeps/s390/s390-64/start.S @@ -0,0 +1,100 @@ +/* Startup code compliant to the 64 bit S/390 ELF ABI. + Copyright (C) 2001-2017 Free Software Foundation, Inc. + Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + In addition to the permissions in the GNU Lesser General Public + License, the Free Software Foundation gives you unlimited + permission to link the compiled version of this file with other + programs, and to distribute those programs without any restriction + coming from the use of this file. (The GNU Lesser General Public + License restrictions do apply in other respects; for example, they + cover modification of the file, and distribution when not linked + into another program.) + + Note that people who make modified versions of this file are not + obligated to grant this special exception for their modified + versions; it is their choice whether to do so. The GNU Lesser + General Public License gives permission to release a modified + version without this exception; this exception also makes it + possible to release a modified version which carries forward this + exception. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* + This is the canonical entry point, usually the first thing in the text + segment. Most registers' values are unspecified, except for: + + %r14 Contains a function pointer to be registered with `atexit'. + This is how the dynamic linker arranges to have DT_FINI + functions called for shared libraries that have been loaded + before this code runs. + + %r15 The stack contains the arguments and environment: + 0(%r15) argc + 8(%r15) argv[0] + ... + (8*argc)(%r15) NULL + (8*(argc+1))(%r15) envp[0] + ... + NULL +*/ + + .text + .globl _start + .type _start,@function +_start: + /* Load argc and argv from stack. */ + la %r4,8(%r15) # get argv + lg %r3,0(%r15) # get argc + + /* Align the stack to a double word boundary. */ + lghi %r0,-16 + ngr %r15,%r0 + + /* Setup a stack frame and a parameter area. */ + aghi %r15,-176 # make room on stack + xc 0(8,%r15),0(%r15) # clear back-chain + + /* Set up arguments for __libc_start_main: + main, argc, argv, envp, _init, _fini, rtld_fini, stack_end + Note that envp will be determined later in __libc_start_main. + */ + stmg %r14,%r15,160(%r15) # store rtld_fini/stack_end to parameter area + la %r7,160(%r15) + larl %r6,__libc_csu_fini # load pointer to __libc_csu_fini + larl %r5,__libc_csu_init # load pointer to __libc_csu_init + + /* Ok, now branch to the libc main routine. */ +#ifdef PIC + larl %r2,main@GOTENT # load pointer to main + lg %r2,0(%r2) + brasl %r14,__libc_start_main@plt +#else + larl %r2,main # load pointer to main + brasl %r14,__libc_start_main +#endif + + /* Crash if __libc_start_main returns. */ + .word 0 + + /* Define a symbol for the first piece of initialized data. */ + .data + .globl __data_start +__data_start: + .long 0 + .weak data_start + data_start = __data_start |