kernel: spawn: Add proper spawn impl + SYS_spawn

This commit introduces a more complete spawn implementation as well as
the SYS_spawn syscall and a libc interface.

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

3 files changed, 41 insertions, 0 deletions

diff --git a/sys/include/sys/proc.h b/sys/include/sys/proc.h
index 4024879..1b59de9 100644
--- a/sys/include/sys/proc.h
+++ b/sys/include/sys/proc.h
@@ -64,6 +64,7 @@ struct proc {
     struct trapframe tf;
     struct pcb pcb;
     struct proc *parent;
+    void *spawn_data;
     size_t priority;
     int exit_status;
     bool rested;
@@ -84,6 +85,7 @@ struct proc {
 #define PROC_WAITED     BIT(4)  /* Being waited on by parent */
 
 struct proc *this_td(void);
+struct proc *get_child(struct proc *cur, pid_t pid);
 int md_spawn(struct proc *p, struct proc *parent, uintptr_t ip);
 
 scret_t sys_spawn(struct syscall_args *scargs);
diff --git a/sys/include/sys/spawn.h b/sys/include/sys/spawn.h
new file mode 100644
index 0000000..3828d5c
--- /dev/null
+++ b/sys/include/sys/spawn.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2023-2025 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.
+ */
+
+#ifndef _SYS_SPAWN_H_
+#define _SYS_SPAWN_H_
+
+#include <sys/types.h>
+
+#if !defined(_KERNEL)
+pid_t spawn(const char *pathname, int flags);
+#endif  /* _KERNEL */
+#endif  /* !_SYS_SPAWN_H_ */
diff --git a/sys/include/sys/syscall.h b/sys/include/sys/syscall.h
index 2b98df7..16c4b17 100644
--- a/sys/include/sys/syscall.h
+++ b/sys/include/sys/syscall.h
@@ -46,6 +46,7 @@
 #define SYS_stat    5
 #define SYS_sysctl  6
 #define SYS_write   7
+#define SYS_spawn   8
 
 #if defined(_KERNEL)
 /* Syscall return value and arg type */