1 /*
2  * Copyright (c) 2012 Travis Geiselbrecht
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files
6  * (the "Software"), to deal in the Software without restriction,
7  * including without limitation the rights to use, copy, modify, merge,
8  * publish, distribute, sublicense, and/or sell copies of the Software,
9  * and to permit persons to whom the Software is furnished to do so,
10  * subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22  */
23 #include <debug.h>
24 #include <compiler.h>
25 #include <stdint.h>
26 
27 /* externals */
28 extern unsigned int __data_start_rom, __data_start, __data_end;
29 extern unsigned int __bss_start, __bss_end;
30 
31 extern void lk_main(void) __NO_RETURN __EXTERNALLY_VISIBLE;
32 
_start(void)33 void _start(void)
34 {
35     /* copy data from rom */
36     if (&__data_start != &__data_start_rom) {
37         unsigned int *src = &__data_start_rom;
38         unsigned int *dest = &__data_start;
39 
40         while (dest != &__data_end)
41             *dest++ = *src++;
42     }
43 
44     /* zero out bss */
45     unsigned int *bss = &__bss_start;
46     while (bss != &__bss_end)
47         *bss++ = 0;
48 
49     lk_main();
50 }
51