1 files changed, 82 insertions, 0 deletions
diff --git a/lib/libc/aarch64/gen/makecontext.c b/lib/libc/aarch64/gen/makecontext.c
new file mode 100644
index 000000000000..8c9b4edd7a15
--- /dev/null
+++ b/lib/libc/aarch64/gen/makecontext.c
@@ -0,0 +1,82 @@
+/*-
+ * Copyright (c) 2015 The FreeBSD Foundation
+ *
+ * This software was developed by Andrew Turner under
+ * sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ */
+
+#include <sys/param.h>
+
+#include <machine/armreg.h>
+
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <ucontext.h>
+
+void _ctx_start(void);
+
+void
+ctx_done(ucontext_t *ucp)
+{
+
+	if (ucp->uc_link == NULL) {
+		exit(0);
+	} else {
+		setcontext((const ucontext_t *)ucp->uc_link);
+		abort();
+	}
+}
+
+__weak_reference(__makecontext, makecontext);
+
+void
+__makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
+{
+	struct gpregs *gp;
+	va_list ap;
+	int i;
+
+	/* A valid context is required. */
+	if (ucp == NULL)
+		return;
+
+	if ((argc < 0) || (argc > 8))
+		return;
+
+	gp = &ucp->uc_mcontext.mc_gpregs;
+
+	va_start(ap, argc);
+	/* Pass up to eight arguments in x0-7. */
+	for (i = 0; i < argc && i < 8; i++)
+		gp->gp_x[i] = va_arg(ap, uint64_t);
+	va_end(ap);
+
+	/* Set the stack */
+	gp->gp_sp = STACKALIGN(ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+	/* Arrange for return via the trampoline code. */
+	gp->gp_elr = (__register_t)_ctx_start;
+	gp->gp_x[19] = (__register_t)func;
+	gp->gp_x[20] = (__register_t)ucp;
+}