kern: proc: Add initial spawn function

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

2 files changed, 54 insertions, 0 deletions

diff --git a/src/sys/include/sys/proc.h b/src/sys/include/sys/proc.h
index d93f490..fe45506 100644
--- a/src/sys/include/sys/proc.h
+++ b/src/sys/include/sys/proc.h
@@ -136,6 +136,17 @@ int proc_add_range(struct proc *procp, vaddr_t va, paddr_t pa, size_t len);
 int proc_kill(struct proc *procp, int status);
 
 /*
+ * Spawn a process from a binary
+ *
+ * @path: Path to binary
+ * @envp: Environment block pointer
+ *
+ * Returns the PID of the new process on success,
+ * otherwise a less than zero value on error
+ */
+int proc_spawn(const char *path, struct penv_blk *envbp);
+
+/*
  * Initialize machine dependent state of a process
  *
  * @procp: New process data is written here
diff --git a/src/sys/os/os_proc.c b/src/sys/os/os_proc.c
index ad591e6..e32e59c 100644
--- a/src/sys/os/os_proc.c
+++ b/src/sys/os/os_proc.c
@@ -32,9 +32,13 @@
 #include <sys/errno.h>
 #include <sys/cdefs.h>
 #include <sys/queue.h>
+#include <sys/panic.h>
 #include <sys/proc.h>
+#include <sys/cpuvar.h>
+#include <os/systm.h>
 #include <vm/vm.h>
 #include <vm/physseg.h>
+#include <os/elfload.h>
 #include <os/signal.h>
 #include <os/kalloc.h>
 #include <os/filedesc.h>
@@ -169,3 +173,42 @@ proc_check_addr(struct proc *proc, uintptr_t addr, size_t len)
 
     return -EFAULT;
 }
+
+int
+proc_spawn(const char *path, struct penv_blk *envbp)
+{
+    struct pcore *core;
+    struct loaded_elf elf;
+    struct proc *proc;
+    int error;
+
+    if (path == NULL) {
+        return -EINVAL;
+    }
+
+    /* Allocate a new process */
+    proc = kalloc(sizeof(*proc));
+    if (proc == NULL) {
+        return -ENOMEM;
+    }
+
+    proc_init(proc, 0);
+    error = elf_load(path, proc, &elf);
+    if (error < 0) {
+        kfree(proc);
+        return error;
+    }
+
+    core = cpu_sched();
+    if (__unlikely(core == NULL)) {
+        panic("spawn: failed to arbitrate core\n");
+    }
+
+    if (envbp != NULL) {
+        memcpy(&proc->envblk, envbp, sizeof(proc->envblk));
+    }
+
+    md_set_ip(proc, elf.entrypoint);
+    sched_enq(&core->scq, proc);
+    return proc->pid;
+}