Add template for futex syscall

Signed-off-by: Jean-Pierre Miceli <jean-pierre.miceli@heig-vd.ch>

Author: jmi-reds

so3/include/futex.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2014-2018 Daniel Rossier <daniel.rossier@heig-vd.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifndef FUTEX_H
+#define FUTEX_H
+
+#include <timer.h>
+#include <syscall.h>
+
+/* Commands */
+#define FUTEX_WAIT		0
+#define FUTEX_WAKE		1
+#define FUTEX_FD		2
+#define FUTEX_REQUEUE		3
+#define FUTEX_CMP_REQUEUE	4
+#define FUTEX_WAKE_OP		5
+#define FUTEX_LOCK_PI		6
+#define FUTEX_UNLOCK_PI		7
+#define FUTEX_TRYLOCK_PI	8
+#define FUTEX_WAIT_BITSET	9
+
+#define FUTEX_PRIVATE_FLAG 128
+#define FUTEX_CLOCK_REALTIME	256
+#define FUTEX_CMD_MASK		~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
+
+
+SYSCALL_DECLARE(futex, u32 *uaddr, int op, u32 val, const struct timespec * utime,
+		u32 *uaddr2, u32 val3)
+
+#endif /* FUTEX_H */

so3/kernel/Makefile

@@ -8,6 +8,7 @@ obj-y += 	main.o \
 		thread.o \
 		schedule.o \
 		mutex.o  \
+		futex.o  \
 		spinlock.o \
 		syscalls.o \
 		softirq.o \

so3/kernel/futex.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2025 Jean-Pierre Miceli <jean-pierre.miceli@heig-vd.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <errno.h>
+#include <futex.h>
+
+SYSCALL_DEFINE6(futex, u32 *, uaddr, int, op, u32, val,
+		const struct timespec *, utime,
+		u32 *, uaddr2, u32, val3)
+{
+
+	// unsigned int flags = futex_to_flags(op);
+	int cmd = op & FUTEX_CMD_MASK;
+
+	switch (cmd) {
+	case FUTEX_WAIT:
+		break;
+	case FUTEX_WAKE:
+		break;
+	default:
+		printk("Futex cmd '%d' not supported !\n");
+		return -EINVAL;
+	}
+
+	return -ENOSYS;
+}
+
+
+

so3/kernel/syscalls.c

@@ -28,6 +28,7 @@
 #include <signal.h>
 #include <timer.h>
 #include <net.h>
+#include <futex.h>
 #include <syscall.h>
 
 extern void __get_syscall_args_ext(uint32_t *syscall_no);

so3/syscall.tbl

@@ -37,6 +37,7 @@ newfstatat
 mmap
 mmap2
 nanosleep
+futex
 pipe                    IPC_PIPE
 pipe2                   IPC_PIPE
 rt_sigaction            IPC_SIGNAL