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Diffstat (limited to 'libgloss/epiphany/sbrk.c')
| -rw-r--r-- | libgloss/epiphany/sbrk.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/libgloss/epiphany/sbrk.c b/libgloss/epiphany/sbrk.c new file mode 100644 index 000000000..4880c0f8c --- /dev/null +++ b/libgloss/epiphany/sbrk.c @@ -0,0 +1,165 @@ +/* EPIPHANY implementation of _sbrk () + + Copyright (c) 2011, Adapteva, Inc. + All rights reserved. + + Contributor Jeremy Bennett <jeremy.bennett@embecosm.com> for Adapteva Inc + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + * Neither the name of Adapteva nor the names of its contributors may be + used to endorse or promote products derived from this software without + specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. */ +/* ------------------------------------------------------------------------- */ +/* This implementation is suitable for use with the Verilator simulation of + the EPIPHANY. + + Commenting suitable for processing by Doxygen is provided throughout. */ +/* ------------------------------------------------------------------------- */ +#include <sys/types.h> +#include <errno.h> +#include <stddef.h> + +/* ------------------------------------------------------------------------- */ +/*!Increase program data space + + This is a minimal implementation. Assuming the heap is growing upwards + from __heap_start towards __heap_end. + See linker file for definition. + + @param[in] incr The number of bytes to increment the stack by. + + @return A pointer to the start of the new block of memory */ +/* ------------------------------------------------------------------------- */ +void * +_sbrk (int incr) +{ + extern char __heap_start;//set by linker + extern char __heap_end;//set by linker + + static char *heap_end; /* Previous end of heap or 0 if none */ + char *prev_heap_end; + + if (0 == heap_end) { + heap_end = &__heap_start; /* Initialize first time round */ + } + + prev_heap_end = heap_end; + heap_end += incr; + //check + if( heap_end < (&__heap_end)) { + + } else { + errno = ENOMEM; + return (char*)-1; + } + return (void *) prev_heap_end; + +} /* _sbrk () */ + + + +///* sbrk support */ +// +///* The current plan is to have one sbrk handler for all cpus. +// Hence use `asm' for each global variable here to avoid the cpu prefix. +// We can't intrude on the user's namespace (another reason to use asm). */ +// +//#include <sys/types.h> +///*#include <sys/syscall.h>*/ +//#include <errno.h> +//#include <stddef.h> +// +///* These variables are publicly accessible for debugging purposes. +// The user is also free to set sbrk_size to something different. +// See mem-layout.c. */ +// +//extern int sbrk_size asm ("sbrk_size"); +// +//caddr_t sbrk_start asm ("sbrk_start"); +//caddr_t sbrk_loc asm ("sbrk_loc"); +//extern char end; /* Defined by linker. */ +// +///*caddr_t _sbrk_r (struct _reent *, size_t) asm ("__sbrk_r");*/ +// +// +///* This symbol can be defined with the --defsym linker option. */ +//extern char __heap_end __attribute__((weak)); +// +// +///* FIXME: We need a semaphore here. */ +// +//caddr_t +//_sbrk_r (struct _reent *r, size_t nbytes) +//{ +// extern char end; /* Defined by linker. */ +// static char *heap_end; /* Previous end of heap or 0 if none */ +// char *prev_heap_end; +// register char* stack asm("sp"); +// +// if (0 == heap_end) +// { +// heap_end = &end; /* Initialize first time round */ +// } +// +// prev_heap_end = heap_end; +// +// if (stack < (prev_heap_end+nbytes)) { +// /* heap would overlap the current stack depth. +// * Future: use sbrk() system call to make simulator grow memory beyond +// * the stack and allocate that +// */ +// errno = ENOMEM; +// return (char*)-1; +// } +// +// heap_end += nbytes; +// +// return (caddr_t) prev_heap_end; +// +//} /* _sbrk () */ + + +//caddr_t +//_sbrk_r (struct _reent *r, size_t nbytes) +//{ +// caddr_t result; +// +// void *heap_end; +// +// heap_end = &__heap_end; +// if (!heap_end) +// heap_end = sbrk_start + sbrk_size; +// if ( +// /* Ensure we don't underflow. */ +// sbrk_loc + nbytes < sbrk_start +// /* Ensure we don't overflow. */ +// || sbrk_loc + nbytes > (caddr_t)heap_end) +// { +// errno = ENOMEM; +// return ((caddr_t) -1); +// } +// +// if (0 == sbrk_loc) +// sbrk_loc = &end; /* Initialize first time round */ +// result = sbrk_loc; +// sbrk_loc += nbytes; +// return result; +//} |