Last change
on this file since 641 was
444,
checked in by satin@…, 7 years ago
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add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
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File size:
1.4 KB
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Rev | Line | |
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[444] | 1 | /* sbrk.c -- allocate memory dynamically. |
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| 2 | * |
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| 3 | * Copyright (c) 2008 Anthony Green |
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| 4 | * |
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| 5 | * The authors hereby grant permission to use, copy, modify, distribute, |
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| 6 | * and license this software and its documentation for any purpose, provided |
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| 7 | * that existing copyright notices are retained in all copies and that this |
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| 8 | * notice is included verbatim in any distributions. No written agreement, |
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| 9 | * license, or royalty fee is required for any of the authorized uses. |
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| 10 | * Modifications to this software may be copyrighted by their authors |
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| 11 | * and need not follow the licensing terms described here, provided that |
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| 12 | * the new terms are clearly indicated on the first page of each file where |
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| 13 | * they apply. |
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| 14 | */ |
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| 15 | #include <errno.h> |
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| 16 | #include "glue.h" |
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| 17 | |
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| 18 | /* just in case, most boards have at least some memory */ |
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| 19 | #ifndef RAMSIZE |
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| 20 | # define RAMSIZE (caddr_t)0x100000 |
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| 21 | #endif |
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| 22 | |
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| 23 | char *__heap_ptr = (char *)&_end; |
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| 24 | |
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| 25 | /* |
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| 26 | * sbrk -- changes heap size size. Get nbytes more |
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| 27 | * RAM. We just increment a pointer in what's |
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| 28 | * left of memory on the board. |
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| 29 | */ |
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| 30 | char * |
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| 31 | _sbrk (nbytes) |
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| 32 | int nbytes; |
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| 33 | { |
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| 34 | char *base; |
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| 35 | char *sp; |
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| 36 | |
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| 37 | base = __heap_ptr; |
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| 38 | __heap_ptr += nbytes; |
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| 39 | |
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| 40 | return base; |
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| 41 | /* FIXME: We really want to make sure we don't run out of RAM, but this |
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| 42 | * isn't very portable. |
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| 43 | */ |
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| 44 | #if 0 |
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| 45 | if ((RAMSIZE - heap_ptr - nbytes) >= 0) { |
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| 46 | base = heap_ptr; |
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| 47 | heap_ptr += nbytes; |
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| 48 | return (base); |
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| 49 | } else { |
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| 50 | errno = ENOMEM; |
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| 51 | return ((char *)-1); |
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| 52 | } |
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| 53 | #endif |
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| 54 | } |
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