1 files changed, 76 insertions, 23 deletions
diff --git a/kernel/usermode.c b/kernel/usermode.c
index afad9df..339045d 100644
--- a/kernel/usermode.c
+++ b/kernel/usermode.c
@@ -1,32 +1,85 @@
 #include "usermode.h"
+#define FOOLOS_MODULE_NAME "usermode"
+#include "lib/logger/log.h"
+#include "syscalls.h"
 
 
+tss_struct sys_tss; //Define the TSS as a global structure
+
+
+// generic syscall interface!
+int syscall(int call, int p1, int p2, int p3)
+{
+	int ebx; // will hold return value;
+
+	asm("pusha");
+
+	// select syscall
+	asm("mov %0, %%eax"::"m"(call)); 
+
+	// pass params
+	asm("mov %0,%%edx"::"m"(p1));
+	asm("mov %0,%%ecx"::"m"(p2));
+	asm("mov %0,%%ebx"::"m"(p3));
+
+	// interrrupt
+	asm("int $0x80");
+
+	// get return value
+        asm("mov %%ebx, %0": "=b" (ebx));
+
+	asm("popa");
+
+	return ebx;
+}
+int write(int file, char *ptr, int len) 
+{
+    return syscall(SYSCALL_WRITE,file,ptr,len);
+}
+int execve(char *name, char **argv, char **env) 
+{
+    return syscall(SYSCALL_EXECVE,name,argv,env);
+}
+
 void install_tss(int cpu_no){
+
     // now fill each value
     // set values necessary
-    sys_tss.ss0 = 0x10;
-              // now set the IO bitmap (not necessary, so set above limit)       
-    sys_tss.iomap = ( unsigned short ) sizeof( tss_struct ); 
+    sys_tss.ss0 = 0x10; //kernel data
+    sys_tss.esp0 = 0x9000; //kernel stack
+
+    // now set the IO bitmap (not necessary, so set above limit)       
+    // sys_tss.iomap = ( unsigned short ) sizeof( tss_struct ); 
+}
+
+
+void switch_to_user_mode() 
+{
+    char text[]="internal";
+    write(1,text,10);
+    asm_usermode();
+    while(1); // will not be reached?
 }
 
-void switch_to_user_mode() {
-    // Set up a stack structure for switching to user mode.
-    asm volatile("  \
-        cli; \
-        mov $0x23, %ax; \
-        mov %ax, %ds; \
-        mov %ax, %es; \
-        mov %ax, %fs; \
-        mov %ax, %gs; \
-                \ 
-        mov %esp, %eax; \
-        pushl $0x23; \
-        pushl %eax; \
-        pushf; \
-        mov $0x200, %eax; \
-        push %eax; \
-        pushl $0x1B; \
-        push $1f; \
-        iret; \    1: \
-    "); 
+char *argv_init[]={"/bin/init",NULL};
+char *env_init[]={NULL};
+
+// THIS WILL BE RUN IN RING 3!
+void userfunc()
+{
+
+    execve("/bin/init",argv_init,env_init); 
+
+    for(int i=0;i<3;i++)
+    {
+	log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"we are usermode!");
+    }
+
+
+    while(1) 
+    {
+	
+    char text[]="syscalling!";
+    write(1,text,10);
+    }
 }