diff options
Diffstat (limited to 'nuttx/mm/mm_sbrk.c')
| -rw-r--r-- | nuttx/mm/mm_sbrk.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/nuttx/mm/mm_sbrk.c b/nuttx/mm/mm_sbrk.c index c0c640735..f8c22b33a 100644 --- a/nuttx/mm/mm_sbrk.c +++ b/nuttx/mm/mm_sbrk.c @@ -93,9 +93,10 @@ FAR void *mm_sbrk(FAR struct mm_heap_s *heap, intptr_t incr, uintptr_t maxbreak) { uintptr_t brkaddr; + uintptr_t allocbase; unsigned int pgincr; + size_t bytesize; int err; - int ret; DEBUGASSERT(incr >= 0); if (incr < 0) @@ -104,7 +105,10 @@ FAR void *mm_sbrk(FAR struct mm_heap_s *heap, intptr_t incr, goto errout; } - /* Get the current break address (NOTE: assumes region 0) */ + /* Get the current break address (NOTE: assumes region 0). If + * the memory manager is uninitialized, mm_brkaddr() will return + * zero. + */ brkaddr = (uintptr_t)mm_brkaddr(heap, 0); if (incr > 0) @@ -122,19 +126,35 @@ FAR void *mm_sbrk(FAR struct mm_heap_s *heap, intptr_t incr, } /* Allocate the requested number of pages and map them to the - * break address. + * break address. If we provide a zero brkaddr to pgalloc(), it + * will create the first block in the correct virtual address + * space and return the start address of that block. */ - ret = pgalloc(brkaddr, pgincr); - if (ret < 0) + allocbase = pgalloc(brkaddr, pgincr); + if (allocbase == 0) { - err = -ret; + err = EAGAIN; goto errout; } - /* Extend the heap (region 0) */ + /* Has the been been initialized? brkaddr will be zero if the + * memory manager has not yet been initialized. + */ + + bytesize = pgincr << MM_PGSHIFT; + if (brkaddr != 0) + { + /* No... then initialize it now */ - mm_extend(heap, (FAR void *)brkaddr, pgincr << MM_PGSHIFT, 0); + mm_initialize(heap, (FAR void *)allocbase, bytesize); + } + else + { + /* Extend the heap (region 0) */ + + mm_extend(heap, (FAR void *)allocbase, bytesize, 0); + } } return (FAR void *)brkaddr; |