[rtems commit] bsp/riscv: Initialize FPU depending on ISA

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    529154bad207a42a6d0f03343c7e215eab97ced5
Changeset: http://git.rtems.org/rtems/commit/?id=529154bad207a42a6d0f03343c7e215eab97ced5

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Tue Jul 31 09:15:00 2018 +0200

bsp/riscv: Initialize FPU depending on ISA

Initialize fcsr to zero for a defined rounding mode.

Update #3433.

---

 bsps/riscv/riscv/start/start.S | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/bsps/riscv/riscv/start/start.S b/bsps/riscv/riscv/start/start.S
index 290c95a..feb07fe 100644
--- a/bsps/riscv/riscv/start/start.S
+++ b/bsps/riscv/riscv/start/start.S
@@ -48,9 +48,12 @@ SYM(_start):
 	LADDR	gp, __global_pointer$
 	.option	pop
 
-	/* Init FPU unit if it's there */
+	/* Init FPU */
+#ifdef __riscv_flen
 	li	t0, MSTATUS_FS
 	csrs	mstatus, t0
+	csrw	fcsr, zero
+#endif
 
 	/* Set exception handler */
 	LADDR	t0, _RISCV_Exception_handler