kernel: Add fork1()

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 79 insertions, 0 deletions

diff --git a/sys/include/sys/proc.h b/sys/include/sys/proc.h
index db41a4b..c74bca5 100644
--- a/sys/include/sys/proc.h
+++ b/sys/include/sys/proc.h
@@ -53,6 +53,7 @@ struct proc {
 
 struct proc *this_td(void);
 int md_td_init(struct proc *p, struct proc *parent, uintptr_t ip);
+int fork1(struct proc *cur, int flags, void(*ip)(void), struct proc **newprocp);
 
 #endif  /* _KERNEL */
 #endif  /* !_SYS_PROC_H_ */
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
new file mode 100644
index 0000000..64e0caf
--- /dev/null
+++ b/sys/kern/kern_fork.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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/types.h>
+#include <sys/proc.h>
+#include <sys/errno.h>
+#include <sys/sched.h>
+#include <vm/dynalloc.h>
+#include <string.h>
+
+static size_t nthreads = 0;
+
+/*
+ * Fork1 - fork and direct a thread to 'ip'
+ *
+ * @cur: Current process.
+ * @flags: Flags to set.
+ * @ip: Location for new thread to start at.
+ * @newprocp: Will contain new thread if not NULL.
+ */
+int
+fork1(struct proc *cur, int flags, void(*ip)(void), struct proc **newprocp)
+{
+    struct proc *newproc;
+    int status = 0;
+
+    newproc = dynalloc(sizeof(*newproc));
+    if (newproc == NULL)
+        return -ENOMEM;
+
+    /*
+     * We want to zero the proc to ensure it is in known
+     * state. We then want to initialize machine dependent
+     * fields.
+     */
+    memset(newproc, 0, sizeof(*newproc));
+    status = md_td_init(newproc, cur, (uintptr_t)ip);
+    if (status != 0)
+        goto done;
+
+    /* Set proc output if we can */
+    if (newprocp != NULL)
+        *newprocp = newproc;
+
+    newproc->pid = nthreads++;
+    sched_enqueue_td(newproc);
+done:
+    if (status != 0)
+        dynfree(newproc);
+
+    return status;
+}