jos/kern/trapentry.S

/* See COPYRIGHT for copyright information. */

#include <inc/mmu.h>
#include <inc/memlayout.h>
#include <inc/trap.h>

#include <kern/picirq.h>


###################################################################
# exceptions/interrupts
###################################################################

/* TRAPHANDLER defines a globally-visible function for handling a trap.
 * It pushes a trap number onto the stack, then jumps to _alltraps.
 * Use TRAPHANDLER for traps where the CPU automatically pushes an error code.
 *
 * You shouldn't call a TRAPHANDLER function from C, but you may
 * need to _declare_ one in C (for instance, to get a function pointer
 * during IDT setup).  You can declare the function with
 *   void NAME();
 * where NAME is the argument passed to TRAPHANDLER.
 */
#define TRAPHANDLER(name, num)						\
	.globl name;		/* define global symbol for 'name' */	\
	.type name, @function;	/* symbol type is function */		\
	.align 2;		/* align function definition */		\
	name:			/* function starts here */		\
	pushl $(num);							\
	jmp _alltraps

/* Use TRAPHANDLER_NOEC for traps where the CPU doesn't push an error code.
 * It pushes a 0 in place of the error code, so the trap frame has the same
 * format in either case.
 */
#define TRAPHANDLER_NOEC(name, num)					\
	.globl name;							\
	.type name, @function;						\
	.align 2;							\
	name:								\
	pushl $0;							\
	pushl $(num);							\
	jmp _alltraps

.text

.globl sysenter_handler
sysenter_handler:
	push %ebp // holds env's stack pointer
	push %esi // holds the env's return addr
	push %edi
	push %ebx
	push %ecx
	push %edx
	push %eax
	call syscall
	add $0x14, %esp
	pop %edx
	pop %ecx
	sysexit
	
/*
 * Lab 3: Your code here for generating entry points for the different traps.
 */
TRAPHANDLER_NOEC(t_divide, T_DIVIDE);
TRAPHANDLER_NOEC(t_debug, T_DEBUG);
TRAPHANDLER_NOEC(t_nmi, T_NMI);
TRAPHANDLER_NOEC(t_brkpt, T_BRKPT);
TRAPHANDLER_NOEC(t_oflow, T_OFLOW);
TRAPHANDLER_NOEC(t_bound, T_OFLOW);
TRAPHANDLER_NOEC(t_illop, T_OFLOW);
TRAPHANDLER_NOEC(t_device, T_OFLOW);
TRAPHANDLER(t_dblflt, T_OFLOW);
TRAPHANDLER(t_tss, T_TSS);
TRAPHANDLER(t_segnp, T_SEGNP);
TRAPHANDLER(t_stack, T_STACK);
TRAPHANDLER(t_gpflt, T_GPFLT);
TRAPHANDLER(t_pgflt, T_PGFLT);
TRAPHANDLER_NOEC(t_fperr, T_FPERR);
TRAPHANDLER(t_align, T_ALIGN);
TRAPHANDLER_NOEC(t_mchk, T_MCHK);
TRAPHANDLER_NOEC(t_simderr, T_SIMDERR);
TRAPHANDLER_NOEC(t_syscall, T_SYSCALL);
TRAPHANDLER(t_default, T_DEFAULT);

// HINT 1 : TRAPHANDLER_NOEC(t_divide, T_DIVIDE);
//          Do something like this if there is no error code for the trap
// HINT 2 : TRAPHANDLER(t_dblflt, T_DBLFLT);
//          Do something like this if the trap includes an error code..
// HINT 3 : READ Intel's manual to check if the trap includes an error code
//          or not...

/*
 * Lab 3: Your code here for _alltraps
 */

.globl _alltraps
_alltraps:
	sub $0x2, %esp
	pushw %ds
	sub $0x2, %esp
	pushw %es
	pushal
	mov $(GD_KD), %eax
	movw %ax, %ds
	movw %ax, %es
	pushl %esp
	call trap