syscalls.c: Bugfix _sbrk() implementation.

Fix _sbrk() implementation so it properly rejects negative arguments
which would send the program break below the heap start.  Fix
incorrect check against argument causing heap overflow.  Also set
errno properly to ENOMEM when the call fails.

Beginning and end of the heap are now determined by HEAP_START and
HEAP_END macros.  Their current values seem to work OK for heaps on
the internal SRAM, but they'll need to get generalized for Maple
Native.

0 files changed, 0 insertions, 0 deletions