diff options
Diffstat (limited to 'libc/sysdeps/linux/bfin/crt1.S')
-rw-r--r-- | libc/sysdeps/linux/bfin/crt1.S | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/bfin/crt1.S b/libc/sysdeps/linux/bfin/crt1.S new file mode 100644 index 000000000..7b6a99de0 --- /dev/null +++ b/libc/sysdeps/linux/bfin/crt1.S @@ -0,0 +1,74 @@ +/* Initial C runtime code for Blackfin + * + * Copyright (C) 2004-2006 Erik Andersen <andersen@uclibc.org> + * + * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball. + */ + +/* When we enter this piece of code, the user stack looks like this: +* argc argument counter (integer) +* argv[0] program name (pointer) +* argv[1...N] program args (pointers) +* NULL +* env[0...N] environment variables (pointers) +* NULL + +* When we are done here, we want +* R0=argc +* R1=*argv[0] +* R2=*envp[0] +*/ + +#include <features.h> + +.text +.align 2 +.global __start; +.type __start,STT_FUNC; +.global ___uClibc_main; +.type ___uClibc_main,STT_FUNC; + +#if defined(__UCLIBC_CTOR_DTOR__) +.type __init,%function +.type __fini,%function +#else +.weak __init +.weak __fini +#endif + +/* + When we enter, our stack looks like: + [ SP ] + [argc][argv]... + + Call ___uClibc_main(argc, argv, __init, __fini) + R0 R1 R2 stack + + Before we call main, we want: + [ SP ] + [fini][argc][argv] +*/ + +__start: + +/* clear the frame pointer */ + FP = 0; + +/* Load register R0 (argc) from the stack to its final resting place */ + P0 = SP; + R0 = [P0++]; + +/* Copy argv pointer into R1 */ + R1 = P0; + +/* Load __init into R2 */ + R2 = __init; + +/* Load __fini onto the stack */ + P0 = __fini; + [SP--] = P0; + +/* Ok, now run uClibc's main() -- shouldn't return */ + sp += -8; + jump.l ___uClibc_main; +.size __start,.-__start |