LAB 4 IS DONE.

lab/kern/trapentry.S

@@ -0,0 +1,109 @@
+/* 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.
+
+ * tarp handler no error code
+ */
+ 
+#define TRAPHANDLER_NOEC(name, num)					\
+	.globl name;							\
+	.type name, @function;						\
+	.align 2;							\
+	name:								\
+	pushl $0;							\
+	pushl $(num);							\
+	jmp _alltraps
+
+.text
+
+/*
+ * 我们知道哪些trap是有错误代码的？ https://wiki.osdev.org/Exceptions
+ * Lab 3: Your code here for generating entry points for the different traps.
+ */
+TRAPHANDLER_NOEC(divide_handler, T_DIVIDE);
+TRAPHANDLER_NOEC(debug_handler, T_DEBUG);
+TRAPHANDLER_NOEC(nmi_handler, T_NMI);
+TRAPHANDLER_NOEC(brkpt_handler, T_BRKPT);
+TRAPHANDLER_NOEC(oflow_handler, T_OFLOW);
+TRAPHANDLER_NOEC(bound_handler, T_BOUND);
+TRAPHANDLER_NOEC(illop_handler, T_ILLOP);
+TRAPHANDLER_NOEC(device_handler, T_DEVICE);
+TRAPHANDLER(dblflt_handler, T_DBLFLT);
+TRAPHANDLER(tss_handler, T_TSS);
+TRAPHANDLER(segnp_handler, T_SEGNP);
+TRAPHANDLER(stack_handler, T_STACK);
+TRAPHANDLER(gpflt_handler, T_GPFLT);
+TRAPHANDLER(pgflt_handler, T_PGFLT);
+TRAPHANDLER_NOEC(fperr_handler, T_FPERR);
+TRAPHANDLER(align_handler, T_ALIGN);
+TRAPHANDLER_NOEC(mchk_handler, T_MCHK);
+TRAPHANDLER_NOEC(simderr_handler, T_SIMDERR);
+TRAPHANDLER_NOEC(syscall_handler, T_SYSCALL);
+
+// IRQs
+TRAPHANDLER_NOEC(timer_handler, IRQ_OFFSET + IRQ_TIMER);
+TRAPHANDLER_NOEC(kbd_handler, IRQ_OFFSET + IRQ_KBD);
+TRAPHANDLER_NOEC(serial_handler, IRQ_OFFSET + IRQ_SERIAL);
+TRAPHANDLER_NOEC(spurious_handler, IRQ_OFFSET + IRQ_SPURIOUS);
+TRAPHANDLER_NOEC(ide_handler, IRQ_OFFSET + IRQ_IDE);
+TRAPHANDLER_NOEC(error_handler, IRQ_OFFSET + IRQ_ERROR);
+
+
+/*
+Your _alltraps should:
+	1. push values to make the stack look like a struct Trapframe
+	2. load GD_KD into %ds and %es
+	3. pushl %esp to pass a pointer to the Trapframe as an argument to trap()
+	4. call trap (can trap ever return?)
+*/
+
+/*
+ * Lab 3: Your code here for _alltraps
+ *what is padding ? 填充 pushl %ds;小端模式，是指数据的高字节保存在内存的高地址中
+ */
+.globl _alltraps
+_alltraps:
+	
+	pushl %ds;
+	pushl %es;
+	pushal;
+	
+	movw $GD_KD, %ax;
+	movw %ax, %ds;
+	movw %ax, %es;
+
+	/*push esp, trap 能自己读esp, 我有点觉得是赋值*/
+	pushl %esp;        
+	call trap
+