From a302b48c21aaf08f166b8514705b87f1331c147f Mon Sep 17 00:00:00 2001
From: Jeff Johnston <jjohnstn@redhat.com>
Date: Fri, 19 Jan 2001 01:25:13 +0000
Subject: 2001-01-18  Jeff Johnston  <jjohnstn@redhat.com>

        * libc/sys/arc/Makefile.am: New file.
        * libc/sys/arc/Makefile.in: Ditto.
        * libc/sys/arc/aclocal.m4: Ditto.
        * libc/sys/arc/configure: Ditto.
        * libc/sys/arc/configure.in: Ditto.
        * libc/sys/arc/crt0.S: Ditto.
        * libc/sys/arc/isatty.c: Ditto.
        * libc/sys/arc/mem-layout.c: Ditto.
        * libc/sys/arc/sbrk.c: Ditto.
        * libc/sys/arc/syscalls.c: Ditto.
        * libc/sys/arc/sys/syscall.h: Ditto.
---
 newlib/libc/sys/arc/sbrk.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 newlib/libc/sys/arc/sbrk.c

(limited to 'newlib/libc/sys/arc/sbrk.c')

diff --git a/newlib/libc/sys/arc/sbrk.c b/newlib/libc/sys/arc/sbrk.c
new file mode 100644
index 000000000..9f863cded
--- /dev/null
+++ b/newlib/libc/sys/arc/sbrk.c
@@ -0,0 +1,43 @@
+/* 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");
+
+/*caddr_t _sbrk_r (struct _reent *, size_t) asm ("__sbrk_r");*/
+
+/* FIXME: We need a semaphore here.  */
+
+caddr_t
+_sbrk_r (struct _reent *r, size_t nbytes)
+{
+  caddr_t result;
+
+  if (
+      /* Ensure we don't underflow.  */
+      sbrk_loc + nbytes < sbrk_start
+      /* Ensure we don't overflow.  */
+      || sbrk_loc + nbytes > sbrk_start + sbrk_size)
+    {
+      errno = ENOMEM;
+      return ((caddr_t) -1);
+    }
+
+  result = sbrk_loc;
+  sbrk_loc += nbytes;
+  return result;
+}
-- 
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