1 /* Startup code compliant to the ELF RISC-V ABI.
2 Copyright (C) 1995-2018 Free Software Foundation, Inc.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 In addition to the permissions in the GNU Lesser General Public
10 License, the Free Software Foundation gives you unlimited
11 permission to link the compiled version of this file with other
12 programs, and to distribute those programs without any restriction
13 coming from the use of this file. (The GNU Lesser General Public
14 License restrictions do apply in other respects; for example, they
15 cover modification of the file, and distribution when not linked
16 into another program.)
18 Note that people who make modified versions of this file are not
19 obligated to grant this special exception for their modified
20 versions; it is their choice whether to do so. The GNU Lesser
21 General Public License gives permission to release a modified
22 version without this exception; this exception also makes it
23 possible to release a modified version which carries forward this
26 The GNU C Library is distributed in the hope that it will be useful,
27 but WITHOUT ANY WARRANTY; without even the implied warranty of
28 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
29 Lesser General Public License for more details.
31 You should have received a copy of the GNU Lesser General Public
32 License along with the GNU C Library. If not, see
33 <http://www.gnu.org/licenses/>. */
35 #define __ASSEMBLY__ 1
40 /* The entry point's job is to call __uClibc_main. Per the ABI,
41 a0 contains the address of a function to be passed to atexit.
42 __uClibc_main wants this in a5. */
46 .type _start,%function
53 mv a5, a0 /* rtld_fini. */
54 /* main may be in a shared library. */
56 REG_L a1, 0(sp) /* argc. */
57 addi a2, sp, SZREG /* argv. */
58 andi sp, sp, ALMASK /* Align stack. */
61 mv a6, sp /* stack_end. */
63 tail __uClibc_main@plt
67 /* Dynamic links need the global pointer to be initialized prior to calling
68 any shared library's initializers, so we use preinit_array to load it.
69 This doesn't cut it for static links, though, since the global pointer
70 needs to be initialized before calling __libc_start_main in that case.
71 So we redundantly initialize it at the beginning of _start. */
76 lla gp, __global_pointer$
80 .section .preinit_array,"aw"
83 /* Define a symbol for the first piece of initialized data. */
88 data_start = __data_start