From 51621c156c03feff0d5e4246ecd2e18473fd347d Mon Sep 17 00:00:00 2001
From: Patrick Williams <iawillia@us.ibm.com>
Date: Thu, 9 Sep 2010 15:21:12 -0500
Subject: Add task_exec system call.

---
 src/include/sys/task.h    |  2 ++
 src/include/sys/vfs.h     |  1 +
 src/lib/syscall_task.C    | 31 +++++++++++++++++++++++++++++++
 src/sys/init/init_main.C  | 14 +++++++++++++-
 src/sys/vfs/vfs_main.C    | 22 ++++++++++++++++++++++
 src/usr/example/example.C |  1 +
 6 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/src/include/sys/task.h b/src/include/sys/task.h
index 520008e6d..ca1475b27 100644
--- a/src/include/sys/task.h
+++ b/src/include/sys/task.h
@@ -16,6 +16,8 @@ void task_end();
 tid_t task_gettid();
 cpuid_t task_getcpuid();
 
+tid_t task_exec(const char*, void*);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/include/sys/vfs.h b/src/include/sys/vfs.h
index e596030fe..d55a44710 100644
--- a/src/include/sys/vfs.h
+++ b/src/include/sys/vfs.h
@@ -24,6 +24,7 @@ enum VfsMessages
 {
     VFS_MSG_REGISTER_MSGQ,
     VFS_MSG_RESOLVE_MSGQ,
+    VFS_MSG_EXEC,
 };
 
 struct VfsSystemModule
diff --git a/src/lib/syscall_task.C b/src/lib/syscall_task.C
index a6b575b5e..eedd78235 100644
--- a/src/lib/syscall_task.C
+++ b/src/lib/syscall_task.C
@@ -3,6 +3,8 @@
 #include <kernel/task.H>
 #include <kernel/taskmgr.H>
 #include <kernel/cpu.H>
+#include <sys/vfs.h>
+#include <sys/msg.h>
 
 using namespace Systemcalls;
 
@@ -40,3 +42,32 @@ cpuid_t task_getcpuid()
     asm volatile("addi %0, 13, 0" : "=r"(task));
     return task->cpu->cpu;
 }
+
+tid_t task_exec(const char* file, void* ptr)
+{
+    // The VFS process is responsible for finding the module and creating the
+    // new process.  So, we send a message over to that process.
+    
+    tid_t child = -1; 
+    
+    // Create message, send.
+    msg_q_t vfsQ = (msg_q_t)_syscall0(MSGQ_RESOLVE_ROOT);
+    msg_t* msg = msg_allocate();
+    msg->type = VFS_MSG_EXEC;
+    msg->data[0] = (uint64_t) file;
+    msg->data[1] = (uint64_t) ptr;
+    int rc = msg_sendrecv(vfsQ, msg);
+
+    if (0 == rc)
+    {
+	// Get child ID from message data 0.
+	child = (tid_t) msg->data[0];
+    }
+    else
+    {
+	child = rc;
+    }
+    
+    msg_free(msg);
+    return child;
+}
diff --git a/src/sys/init/init_main.C b/src/sys/init/init_main.C
index 72bfc64a8..ef9dfb1e7 100644
--- a/src/sys/init/init_main.C
+++ b/src/sys/init/init_main.C
@@ -1,5 +1,8 @@
 #include <kernel/console.H>  // TODO : Remove this.
 
+#include <kernel/syscalls.H>
+#include <sys/syscall.h>
+
 #include <sys/task.h>
 #include <sys/mutex.h>
 #include <sys/msg.h>
@@ -7,6 +10,7 @@
 
 mutex_t global_mutex;
 
+/*
 void init_child(void* unused)
 {
     mutex_lock(global_mutex);
@@ -15,6 +19,7 @@ void init_child(void* unused)
     for (volatile int i = 0 ; i < 100000; i++);
     task_end();
 }
+*/
 
 void vfs_main(void*);
 
@@ -24,7 +29,12 @@ void init_main(void* unused)
     
     printk("Bringing up VFS..."); 
     task_create(&vfs_main, NULL);
-    task_yield(); // TODO... add a barrier to ensure VFS is fully up.
+    
+    // TODO... add a barrier to ensure VFS is fully up.
+    while (NULL == _syscall0(Systemcalls::MSGQ_RESOLVE_ROOT));
+	task_yield(); 
+
+
 /* 
     uint64_t* mmio_addr = (uint64_t*) mmio_map((void*)0x800000000, 1);
     printk("MMIO Access %llx\n", *mmio_addr);
@@ -51,6 +61,8 @@ void init_main(void* unused)
     }
 */
 
+    task_exec("libexample.so", NULL);
+
     while(1)
 	task_yield();
 }
diff --git a/src/sys/vfs/vfs_main.C b/src/sys/vfs/vfs_main.C
index 481df1101..0b41bb631 100644
--- a/src/sys/vfs/vfs_main.C
+++ b/src/sys/vfs/vfs_main.C
@@ -2,6 +2,7 @@
 
 #include <sys/msg.h>
 #include <sys/vfs.h>
+#include <sys/task.h>
 
 #include <util/locked/list.H>
 #include <kernel/console.H>  // TODO : Remove this.
@@ -92,6 +93,27 @@ void vfs_main(void* unused)
 		    msg_respond(vfsMsgQ, msg);		    
 		}
 		break;
+	    
+	    case VFS_MSG_EXEC:
+		{
+		    printk("VFS: Got exec request of %s\n", 
+		           (const char*)msg->data[0]);
+		    VfsSystemModule* module = &VFS_MODULES[0];
+		    tid_t child = -1;
+		    while ('\0' != module->module[0])
+		    {
+			if (0 == strcmp((const char*) msg->data[0], 
+					module->module))
+			{
+			    child = task_create(module->start,
+					        (void*) msg->data[1]);
+			    break;
+			}
+		    }
+		    msg->data[0] = child;
+		    msg_respond(vfsMsgQ, msg);
+		}
+		break;
 
 	    default:
 		msg_free(msg);
diff --git a/src/usr/example/example.C b/src/usr/example/example.C
index 18095ac5b..2fd0ef367 100644
--- a/src/usr/example/example.C
+++ b/src/usr/example/example.C
@@ -24,5 +24,6 @@ void _init(void*)
 extern "C"
 void _start(void*)
 {
+    printk("Executing example module.\n");
     task_end();
 }
-- 
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