/*type tells what to do. address1,2,3 are parameters - the values
passed in bx,cx, and dx */
void handleinterrupt21(char type, char* address1, char* address2, char* address3)
{
if (type==1)
bios_printstr(address1);
else if (type==2)
readstring(address1);
else if (type==3)
readfile(address1,address2);
else if (type==4)
writefile(address1,address2,address3);
else if (type==5)
delfile(address1);
else if (type==6)
executeprogram(address1,address2,0);
else if (type==7)
terminateprogram();
else if (type==8)
executeprogram(address1,address2,1);
else if (type==9)
kill(address1);
else if (type==10)
makedir(address1,address2);
else
bios_printstr("ERROR: Invalid interrupt 21 code\r\n\0");
}
void dokernel()
{
/*placeholder for the shell*/
char file[12800];
/*some friendly startup messages*/
bios_printstr("\r\nBuild an Operating System from Scratch Project\r\n\0");
bios_printstr("Written by Michael Black, December, 2007\r\n\n\0");
bios_printstr("Starting the kernel\r\n\0");
/*make the process table*/
initialize_process_table();
bios_printstr("Process table is initialized\r\n\0");
/*install the ISR for interrupt 21*/
makeinterrupt21();
int21(1,"Interrupt 21 is installed\r\n\0");
int21(1,"Kernel set up is completed\r\n\0");
int21(1,"Loading the shell into memory\r\n\0");
/*start the shell*/
/*load it into file[]*/
int21(3,"SHELL\0",file);
/*load it to memory and schedule it to be executed*/
int21(6,file,12800,"SHELL\0");
/*install an ISR for the timer - this will call the scheduler*/
maketimerinterrupt();
int21(1,"Timer interrupt is installed\r\n\0");
int21(1,"\r\nThe shell is starting. The kernel will stay in the background.\r\n\n\0");
}
void showrunningprocess()
{
bios_printstr("entra a la interrupcion en el kernel\r\n\0");
}