diff options
Diffstat (limited to 'libgloss/mips/hal/syscalls.c')
| -rw-r--r-- | libgloss/mips/hal/syscalls.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/libgloss/mips/hal/syscalls.c b/libgloss/mips/hal/syscalls.c new file mode 100644 index 0000000..7c3ffec --- /dev/null +++ b/libgloss/mips/hal/syscalls.c @@ -0,0 +1,52 @@ +#include <_ansi.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <mips/hal.h> + +extern char _end[]; + +/* FIXME: This is not ideal, since we do a get_ram_range() call for + every sbrk() call. */ +char * +sbrk (int nbytes) +{ + static char *heap_ptr = NULL; + static char *heap_start = NULL; + static unsigned long heap_size = 0; + char *base; + ptrdiff_t avail = 0; + void *ram_base; + void *ram_extent; + + if (heap_start == NULL) + { + _get_ram_range (&ram_base, &ram_extent); + + /* If the _end symbol is within the RAM then use _end. */ + if ((void*)_end > ram_base && (void*)_end < ram_extent) + { + heap_start = _end; + heap_ptr = _end; + heap_size = ram_extent - (void*)_end; + } + else + { + heap_start = ram_base; + heap_ptr = ram_base; + heap_size = ram_extent - ram_base; + } + } + + if ((heap_ptr >= heap_start) && + (heap_ptr < (heap_start + heap_size))) { + avail = (heap_start + heap_size) - heap_ptr; + base = heap_ptr; + } /* else will fail since "nbytes" will be greater than zeroed "avail" value */ + + if ((nbytes > avail) || (heap_ptr + nbytes < heap_start)) + base = (char *)-1; + else + heap_ptr += nbytes; + + return base; +} |