+++ /dev/null
-#include <output.h>
-#include <io.h>
-#include <paging.h>
-
-#include "traps.h"
-
-#define CS_SEGSEL 0x10
-
-#define FAULT_WRAPPER(func_name) asm ( \
- ".global " #func_name "_wrapper\n" \
- #func_name "_wrapper:\n" \
- "mov %cr2, %eax\n" \
- "push %eax\n" \
- "push %esp\n" \
- "call " #func_name "\n" \
-); void func_name##_wrapper(void);
-
-#define WRAPPER_INSTALL(idt, idt4_value, func_name, int_number) { \
- *(int *)((void *)idt + (8 * int_number)) = \
- ((int)func_name##_wrapper & 0xFFFF) | \
- (CS_SEGSEL << 16); \
- *(int *)((void *)idt + (8 * int_number) + 4) = \
- ((int)func_name##_wrapper & 0xFFFF0000) | idt4_value; \
-}
-
-/* The 16 bits at offset 4 from the start of an interrupt gate are a
- * bitfield, according to the Intel spec:
- * 15 P - Segment Present - set to 1
- * 14-13 DPL - Descriptor privilege level - set to 11 for trap/int, 00 for IPI
- * 12-8 01111 for 32-bit trap gates, 01110 for 32-bit interrupt gates
- * 7-0 Set to 0
- * Trap: binary 11101111 0000000, hex EF00.
- * Interrupt: binary 11101110 0000000, hex EE00.
- */
-#define TRAP 0xEF00
-#define INTERRUPT 0xEE00
-
-typedef struct trap_t {
- int cr2;
- int error_code;
- int eip;
- int cs;
- int eflags;
- int esp;
- int ss;
-} trap_t;
-
-void die(struct trap_t * trap) {
- outputf("Error %08x %%eip %08x", trap->error_code, trap->eip);
- outputf("%%esp %08x %%eflags %08x", trap->esp, trap->eflags);
- while(1) asm("hlt");
-}
-
-void fault_gp(struct trap_t * trap) {
- outputf("GENERAL PROTECTION FAULT");
- die(trap);
-}
-
-void fault_page(struct trap_t * trap) {
- outputf("PAGE FAULT: %08x", trap->cr2);
- die(trap);
-}
-void fault_divide(struct trap_t * trap) {
- outputf("DIVISION FAULT");
- die(trap);
-}
-void double_fault(struct trap_t * trap) {
- outputf("DOUBLE FAULT");
- die(trap);
-}
-
-FAULT_WRAPPER(fault_gp);
-FAULT_WRAPPER(fault_page);
-FAULT_WRAPPER(fault_divide);
-FAULT_WRAPPER(double_fault);
-
-/* pseudo_descriptor and x86_gate structs from 15-410 basis code. */
-
-struct x86_gate {
-unsigned int filler[2]; //64 bits; or 8 bytes.
-};
-
-static struct x86_gate idt[64];
-
-struct pseudo_descriptor {
- short pad;
- unsigned short limit;
- unsigned long linear_base;
-} __attribute__((packed));
-
-void traps_install(void) {
-
- struct pseudo_descriptor pdesc;
- pdesc.limit = sizeof(idt) - 1;
- pdesc.linear_base = v2p(&idt);
-
- WRAPPER_INSTALL(idt, TRAP, fault_divide, T_DIVIDE_ERROR);
- WRAPPER_INSTALL(idt, TRAP, fault_gp, T_GENERAL_PROTECTION);
- WRAPPER_INSTALL(idt, TRAP, fault_page, T_PAGE_FAULT);
- WRAPPER_INSTALL(idt, TRAP, double_fault, T_DOUBLE_FAULT);
-
- outb(0x80, 0xCC);
- asm volatile("lidt %0" : : "m" (pdesc.limit));
- outb(0x80, 0xCD);
-}