+++ /dev/null
-/*
- * GeekOS IDT initialization code
- * Copyright (c) 2001, David H. Hovemeyer <daveho@cs.umd.edu>
- * $Revision: 1.1 $
- *
- * This is free software. You are permitted to use,
- * redistribute, and modify it as specified in the file "COPYING".
- */
-
-#include <geekos/kassert.h>
-#include <geekos/defs.h>
-#include <geekos/idt.h>
-#include <geekos/serial.h>
-
-/* ----------------------------------------------------------------------
- * Private data and functions
- * ---------------------------------------------------------------------- */
-
-/*
- * Allocated
- */
-//static union IDT_Descriptor s_IDT[ NUM_IDT_ENTRIES ];
-static union IDT_Descriptor *s_IDT = (union IDT_Descriptor *)IDT_LOCATION;
-
-
-/*
- * These symbols are defined in lowlevel.asm, and define the
- * size of the interrupt entry point table and the sizes
- * of the individual entry points. This gives us sufficient
- * information to build the IDT.
- */
-extern char g_entryPointTableStart, g_entryPointTableEnd;
-extern int g_handlerSizeNoErr, g_handlerSizeErr;
-
-/*
- * Table of C interrupt handler functions.
- * Note that this is public only because it is used
- * in lowlevel.asm. Other code should not refer to it.
- */
-Interrupt_Handler g_interruptTable[ NUM_IDT_ENTRIES ];
-
-
-
-void DumpIDT()
-{
- int i;
- Print("IDT Contents:\n");
-
- for (i=0;i<NUM_IDT_ENTRIES/16;i++) {
- if (s_IDT[i].ig.present) {
- Print("%d: segmentselector=%u, offset=%u, offsetLow=%u, segmentSelector=%u, reserved=%u, signature=%u, dpl=%u, present=%u, offsetHigh=%u\n",
- i,
- s_IDT[i].ig.segmentSelector,
- (s_IDT[i].ig.offsetHigh<<16) + s_IDT[i].ig.offsetLow,
- s_IDT[i].ig.offsetLow,
- s_IDT[i].ig.segmentSelector,
- s_IDT[i].ig.reserved,
- s_IDT[i].ig.signature,
- s_IDT[i].ig.dpl,
- s_IDT[i].ig.present,
- s_IDT[i].ig.offsetHigh);
- }
- }
-}
-
-
-void SerialDumpIDT()
-{
- int i;
- SerialPrint("IDT Contents:\n");
-
- for (i=0;i<NUM_IDT_ENTRIES;i++) {
- if (s_IDT[i].ig.present) {
- SerialPrint("%d: segmentselector=%u, offset=%u, offsetLow=%u, segmentSelector=%u, reserved=%u, signature=%u, dpl=%u, present=%u, offsetHigh=%u\n",
- i,
- s_IDT[i].ig.segmentSelector,
- (s_IDT[i].ig.offsetHigh<<16) + s_IDT[i].ig.offsetLow,
- s_IDT[i].ig.offsetLow,
- s_IDT[i].ig.segmentSelector,
- s_IDT[i].ig.reserved,
- s_IDT[i].ig.signature,
- s_IDT[i].ig.dpl,
- s_IDT[i].ig.present,
- s_IDT[i].ig.offsetHigh);
- SerialPrint("\n");
- }
- }
-}
-
-
-
-/* ----------------------------------------------------------------------
- * Public functions
- * ---------------------------------------------------------------------- */
-
-/*
- * Initialize the Interrupt Descriptor Table.
- * This will allow us to install C handler functions
- * for interrupts, both processor-generated and
- * those generated by external hardware.
- */
-void Init_IDT(void)
-{
- int i;
- ushort_t limitAndBase[3];
- ulong_t idtBaseAddr = (ulong_t) s_IDT;
- ulong_t tableBaseAddr = (ulong_t) &g_entryPointTableStart;
- ulong_t addr;
-
- PrintBoth("Initializing IDT\n");
-
- /* Make sure the layout of the entry point table is as we expect. */
- KASSERT(g_handlerSizeNoErr == g_handlerSizeErr);
- KASSERT((&g_entryPointTableEnd - &g_entryPointTableStart) ==
- g_handlerSizeNoErr * NUM_IDT_ENTRIES);
-
- /*
- * Build the IDT.
- * We're taking advantage of the fact that all of the
- * entry points are laid out consecutively, and that they
- * are all padded to be the same size.
- */
- for (i = 0, addr = tableBaseAddr; i < NUM_IDT_ENTRIES; ++i) {
- /*
- * All interrupts except for the syscall interrupt
- * must have kernel privilege to access.
- */
- int dpl = (i == SYSCALL_INT) ? USER_PRIVILEGE : KERNEL_PRIVILEGE;
- Init_Interrupt_Gate(&s_IDT[i], addr, dpl);
- addr += g_handlerSizeNoErr;
- }
-
- /*
- * Cruft together a 16 bit limit and 32 bit base address
- * to load into the IDTR.
- */
- limitAndBase[0] = 8 * NUM_IDT_ENTRIES;
- limitAndBase[1] = idtBaseAddr & 0xffff;
- limitAndBase[2] = idtBaseAddr >> 16;
-
- /* Install the new table in the IDTR. */
- Load_IDTR(limitAndBase);
-}
-
-/*
- * Initialize an interrupt gate with given handler address
- * and descriptor privilege level.
- */
-void Init_Interrupt_Gate(union IDT_Descriptor* desc, ulong_t addr,
- int dpl)
-{
- desc->ig.offsetLow = addr & 0xffff;
- desc->ig.segmentSelector = KERNEL_CS;
- desc->ig.reserved = 0;
- desc->ig.signature = 0x70; /* == 01110000b */
- desc->ig.dpl = dpl;
- desc->ig.present = 1;
- desc->ig.offsetHigh = addr >> 16;
-}
-
-/*
- * Install a C handler function for given interrupt.
- * This is a lower-level notion than an "IRQ", which specifically
- * means an interrupt triggered by external hardware.
- * This function can install a handler for ANY interrupt.
- */
-void Install_Interrupt_Handler(int interrupt, Interrupt_Handler handler)
-{
- KASSERT(interrupt >= 0 && interrupt < NUM_IDT_ENTRIES);
- g_interruptTable[interrupt] = handler;
-}
