#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; //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?
}

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);
    }
}