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author | Jeff Johnston <jjohnstn@redhat.com> | 2004-10-05 20:00:53 +0000 |
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committer | Jeff Johnston <jjohnstn@redhat.com> | 2004-10-05 20:00:53 +0000 |
commit | 49a8b8f05cc85693a05dede399f4dfa5a829b718 (patch) | |
tree | d2aa759d150bf5ff4687433e66bc26cd7ca0f7aa /libgloss/crx/sbrk.c | |
parent | 1185687a7b7f2e707484100d48a68d074d763f15 (diff) | |
download | cygnal-49a8b8f05cc85693a05dede399f4dfa5a829b718.tar.gz cygnal-49a8b8f05cc85693a05dede399f4dfa5a829b718.tar.bz2 cygnal-49a8b8f05cc85693a05dede399f4dfa5a829b718.zip |
2004-10-05 Tomer Levi <Tomer.Levi@nsc.com>
* configure.in: Support crx-*-*.
* configure: regenerate.
* crx/_exit.c: New file.
* crx/_getenv.c: Ditto.
* crx/_rename: Ditto.
* crx/close.c: Ditto.
* crx/configure.in: Ditto.
* crx/crti.S: Ditto.
* crx/crtn.S: Ditto.
* crx/crt0.S: Ditto.
* crx/dvz_hndl.c: Ditto.
* crx/flg_hndl.c: Ditto.
* crx/fstat.c: Ditto.
* crx/getpid.c: Ditto.
* crx/iad_hndl.c: Ditto.
* crx/intable.c: Ditto.
* crx/isatty.c: Ditto.
* crx/kill.c: Ditto.
* crx/lseek.c: Ditto.
* crx/Makefile.in: Ditto.
* crx/open.c: Ditto.
* crx/putnum.c: Ditto.
* crx/read.c: Ditto.
* crx/sbrk.c: Ditto.
* crx/sim.ld: Ditto.
* crx/stat.c: Ditto.
* crx/svc_hndl.c: Ditto.
* crx/time.c: Ditto.
* crx/und_hndl.c: Ditto.
* crx/unlink.c: Ditto.
* crx/write.c: Ditto.
Diffstat (limited to 'libgloss/crx/sbrk.c')
-rw-r--r-- | libgloss/crx/sbrk.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/libgloss/crx/sbrk.c b/libgloss/crx/sbrk.c new file mode 100644 index 000000000..70d5d4f7d --- /dev/null +++ b/libgloss/crx/sbrk.c @@ -0,0 +1,56 @@ +/* sbrk.c -- Implementation of the low-level sbrk() routine + * + * Copyright (c) 2004 National Semiconductor Corporation + * + * The authors hereby grant permission to use, copy, modify, distribute, + * and license this software and its documentation for any purpose, provided + * that existing copyright notices are retained in all copies and that this + * notice is included verbatim in any distributions. No written agreement, + * license, or royalty fee is required for any of the authorized uses. + * Modifications to this software may be copyrighted by their authors + * and need not follow the licensing terms described here, provided that + * the new terms are clearly indicated on the first page of each file where + * they apply. + */ + +#include <errno.h> +#include <stddef.h> /* where ptrdiff_t is defined */ +#include <stdlib.h> + +/* Extend heap space by size bytes. + Return start of new space allocated, or -1 for errors + Error cases: + 1. Allocation is not within heap range */ + +void * sbrk (ptrdiff_t size) +{ + /* + * The following two memory locations should be defined in the linker script file + */ + extern const char _HEAP_START; /* start of heap */ + extern const char _HEAP_MAX; /* end of heap (maximum value of heap_ptr) */ + + static const char * heap_ptr; /* pointer to head of heap */ + const char * old_heap_ptr; + static unsigned char init_sbrk = 0; + + /* heap_ptr is initialized to HEAP_START */ + if (init_sbrk == 0) + { + heap_ptr = &_HEAP_START; + init_sbrk = 1; + } + + old_heap_ptr = heap_ptr; + + if ((heap_ptr + size) > &_HEAP_MAX) + { + /* top of heap is bigger than _HEAP_MAX */ + errno = ENOMEM; + return (void *) -1; + } + + /* success: update heap_ptr and return previous value */ + heap_ptr += size; + return (void *)old_heap_ptr; +} |