RISC-V: Add nanosleep functionality

2 files changed, 13 insertions, 0 deletions

diff --git a/libgloss/riscv/Makefile.in b/libgloss/riscv/Makefile.in
index 2f03f4402..de4ea8d83 100644
--- a/libgloss/riscv/Makefile.in
+++ b/libgloss/riscv/Makefile.in
@@ -7,6 +7,7 @@ gloss_hdrs = \
 
 gloss_srcs = \
 	syscalls.c \
+	nanosleep.c
 
 # Extra files
 
diff --git a/libgloss/riscv/nanosleep.c b/libgloss/riscv/nanosleep.c
new file mode 100644
index 000000000..1a247109c
--- /dev/null
+++ b/libgloss/riscv/nanosleep.c
@@ -0,0 +1,12 @@
+#include <machine/syscall.h>
+#include <sys/time.h>
+
+int
+nanosleep(const struct timespec *rqtp, struct timespec *rmtp)
+{
+  unsigned long current_time, end_time;
+  asm ("rdtime %0" : "+r" (current_time));
+  end_time = current_time + rqtp->tv_sec * 1000000000ULL + rqtp->tv_nsec;
+  while (current_time <= end_time) asm ("rdtime %0" : "+r" (current_time));
+  return 0;
+}