1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2019 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35 #include <sys/cdefs.h>
36
37 /* The size of the thread control block.
38 * TLS relocations are generated relative to
39 * a location this far *before* the first thread
40 * variable (!)
41 * NB: The actual size before tp also includes padding
42 * to align up to the alignment of .tdata/.tbss.
43 */
44 #if __SIZE_WIDTH__ == 32
45 extern char __arm32_tls_tcb_offset;
46 #define TP_OFFSET ((size_t)&__arm32_tls_tcb_offset)
47 #else
48 extern char __arm64_tls_tcb_offset;
49 #define TP_OFFSET ((size_t)&__arm64_tls_tcb_offset)
50 #endif
51
52 #pragma GCC diagnostic ignored "-Warray-bounds"
53
54 static inline void
_set_tls(void * tls)55 _set_tls(void *tls)
56 {
57 __asm__ volatile("msr tpidr_el0, %0" : : "r" (tls - TP_OFFSET));
58 }
59
60 #include "../../crt0.h"
61
62 static void __attribute((used))
_cstart(void)63 _cstart(void)
64 {
65 __start();
66 }
67
68 void __section(".text.init.enter")
_start(void)69 _start(void)
70 {
71 /* Initialize stack */
72 __asm__("adrp x1, __stack");
73 __asm__("add x1, x1, :lo12:__stack");
74 __asm__("mov sp, x1");
75 /* Enable FPU */
76 __asm__("mov x1, #(0x3 << 20)");
77 __asm__("msr cpacr_el1,x1");
78 /* Jump into C code */
79 __asm__("bl _cstart");
80 }
81
