//----------------------------------------------------------------------------//
// GNU GPL OS/K //
// //
// Desc: Interrupt related functions //
// //
// //
// Copyright © 2018-2020 The OS/K Team //
// //
// This file is part of OS/K. //
// //
// OS/K is free software: you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation, either version 3 of the License, or //
// any later version. //
// //
// OS/K is distributed in the hope that it will be useful, //
// but WITHOUT ANY WARRANTY//without even the implied warranty of //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
// GNU General Public License for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with OS/K. If not, see . //
//----------------------------------------------------------------------------//
#include
#include
#include
#include
#include
#include
IdtEntry_t idt[256] = { 0 };
IdtPtr_t _KeIdtPtr;
bool KeIdtIsInitialized = 0;
ulong KeSpuriousCount = 0;
static ISRList_t isrList = { 0 };
static char *ExceptionsChar[32] = {
"Divide Error Fault",
"Debug Exception Trap",
"Non-maskable Interrupt",
"Breakpoint Trap",
"Overflow Trap",
"Bound Range Exceeded Fault",
"Invalid Opcode Fault",
"Device Not Available or No Math Coprocessor Fault",
"Double Fault Abort",
"Coprocessor Segment Overrun Fault (Legacy)",
"Invalid TSS Fault",
"Segment Not Present Fault",
"Stack Segment fault",
"General Protection Fault",
"Page Fault",
"Intel Reserved",
"x87 FPU Floating Point or Math Fault",
"Alignment Check Fault",
"Machine Check Abort",
"SIMD Floating Point Fault",
"Virtualization Exception Fault",
"Intel Reserved",
"Intel Reserved",
"Intel Reserved",
"Intel Reserved",
"Intel Reserved",
"Intel Reserved",
"Intel Reserved",
"Intel Reserved",
"Intel Reserved",
"Security Exception",
"Intel Reserved"
};
static void EnablePIC(void);
static void EarlyExceptionHandler(ISRFrame_t *regs);
static void DoubleFaultHandler(ISRFrame_t *regs);
//
// Registers an isr with his IRQ to handle driver interrupts
//
error_t KeRegisterISR(void (*isr)(ISRFrame_t *regs), uchar isrNo)
{
uchar n = isrList.n;
int OverWriting = 0;
assert(KeIdtIsInitialized); // IDT initialized
if (n == 0) goto settingUp;
for (int i = 0; i < n; i++) {
if (isrNo == isrList.entry[i].isrNo) {
n = i;
OverWriting++;
break;
}
}
if ((n == 255)) // IRQs not filled
return ENOMEM;
settingUp:
isrList.entry[n].isr = isr;
isrList.entry[n].isrNo = isrNo;
if (!OverWriting) isrList.n++;
DebugLog("Interrupt %d registered to function %p\n", isrNo, isr);
return EOK;
}
//
// Installs the IDT in order to activate the interrupts handling
//
void KeSetupIDT(void)
{
// XXX detect the APIC with cpuid and, perhaps, use it !
EnablePIC();
ushort codeSeg = (ushort)(ulong)BtLoaderInfo.codeSegment;
// Set IDT ptr
_KeIdtPtr.limit = (sizeof(IdtEntry_t) * 256) - 1;
_KeIdtPtr.base = &idt;
// Set IDT Exception Gates
KeSetIDTGate(0x00, (ulong)isr0, codeSeg, 0x8E, 2);
KeSetIDTGate(0x01, (ulong)isr1, codeSeg, 0x8E, 2);
KeSetIDTGate(0x02, (ulong)isr2, codeSeg, 0x8E, 2);
KeSetIDTGate(0x03, (ulong)isr3, codeSeg, 0x8E, 2);
KeSetIDTGate(0x04, (ulong)isr4, codeSeg, 0x8E, 2);
KeSetIDTGate(0x05, (ulong)isr5, codeSeg, 0x8E, 2);
KeSetIDTGate(0x06, (ulong)isr6, codeSeg, 0x8E, 2);
KeSetIDTGate(0x07, (ulong)isr7, codeSeg, 0x8E, 2); // XXX device not available, useful for FPU save/restore when multitasking
KeSetIDTGate(0x08, (ulong)isr8, codeSeg, 0x8E, 1); // DOUBLE FAULT
KeSetIDTGate(0x09, (ulong)isr9, codeSeg, 0x8E, 2);
KeSetIDTGate(0x0A, (ulong)isr10, codeSeg, 0x8E, 0); // INVALID TSS
KeSetIDTGate(0x0B, (ulong)isr11, codeSeg, 0x8E, 2);
KeSetIDTGate(0x0C, (ulong)isr12, codeSeg, 0x8E, 1); // STACK SEGMENT FAULT
KeSetIDTGate(0x0D, (ulong)isr13, codeSeg, 0x8E, 2);
KeSetIDTGate(0x0E, (ulong)isr14, codeSeg, 0x8E, 2);
KeSetIDTGate(0x0F, (ulong)isr15, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x10, (ulong)isr16, codeSeg, 0x8E, 2);
KeSetIDTGate(0x11, (ulong)isr17, codeSeg, 0x8E, 2);
KeSetIDTGate(0x12, (ulong)isr18, codeSeg, 0x8E, 2);
KeSetIDTGate(0x13, (ulong)isr19, codeSeg, 0x8E, 2);
KeSetIDTGate(0x14, (ulong)isr20, codeSeg, 0x8E, 2);
KeSetIDTGate(0x15, (ulong)isr21, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x16, (ulong)isr22, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x17, (ulong)isr23, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x18, (ulong)isr24, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x19, (ulong)isr25, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x1A, (ulong)isr26, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x1B, (ulong)isr27, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x1C, (ulong)isr28, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x1D, (ulong)isr29, codeSeg, 0x8E, 2); // INTEL RESERVED
KeSetIDTGate(0x1E, (ulong)isr30, codeSeg, 0x8E, 2);
KeSetIDTGate(0x1F, (ulong)isr31, codeSeg, 0x8E, 2); // INTEL RESERVED
// Set IDT IRQs Gates
KeSetIDTGate(0x20, (ulong)isr32, codeSeg, 0x8E, 0);
KeSetIDTGate(0x21, (ulong)isr33, codeSeg, 0x8E, 3);
KeSetIDTGate(0x22, (ulong)isr34, codeSeg, 0x8E, 3); // NEVER RAISED : cascaded
KeSetIDTGate(0x23, (ulong)isr35, codeSeg, 0x8E, 3);
KeSetIDTGate(0x24, (ulong)isr36, codeSeg, 0x8E, 3);
KeSetIDTGate(0x25, (ulong)isr37, codeSeg, 0x8E, 3);
KeSetIDTGate(0x26, (ulong)isr38, codeSeg, 0x8E, 3);
KeSetIDTGate(0x27, (ulong)isr39, codeSeg, 0x8E, 3);
KeSetIDTGate(0x28, (ulong)isr40, codeSeg, 0x8E, 3);
KeSetIDTGate(0x29, (ulong)isr41, codeSeg, 0x8E, 3);
KeSetIDTGate(0x2A, (ulong)isr42, codeSeg, 0x8E, 3);
KeSetIDTGate(0x2B, (ulong)isr43, codeSeg, 0x8E, 3);
KeSetIDTGate(0x2C, (ulong)isr44, codeSeg, 0x8E, 3);
KeSetIDTGate(0x2D, (ulong)isr45, codeSeg, 0x8E, 3);
KeSetIDTGate(0x2E, (ulong)isr46, codeSeg, 0x8E, 3);
KeSetIDTGate(0x2F, (ulong)isr47, codeSeg, 0x8E, 3);
KeIdtIsInitialized++;
//Setup Early Exception handler
for (uchar i = 0 ; i < 0x20 ; i++) {
KeRegisterISR(EarlyExceptionHandler, i);
}
KeRegisterISR(KeBrkDumpRegisters, 0x3);
KeRegisterISR(DoubleFaultHandler, 0x8);
// Load IDT
KeLoadIDT();
//DebugLog("\tInterrupt table initialized at %p\n", _KeIdtPtr.base);
DebugLog("Interrupts activated\n");
}
//
// Set an interrupt gate
//
void KeSetIDTGate(uchar rank, ulong base, ushort selector, uchar flags, uchar ist)
{
// Set Base Address
idt[rank].baseLow = base & 0xFFFF;
idt[rank].baseMid = (base >> 16) & 0xFFFF;
idt[rank].baseHigh = (base >> 32) & 0xFFFFFFFF;
// Set Selector
idt[rank].selector = selector;
idt[rank].flags = flags;
// Set Reserved Areas to Zero
idt[rank].ist = ist;
idt[rank].reserved = 0;
}
//
// Enable and initializes the PIC to work correctly
//
static void EnablePIC(void)
{
// Set ICW1 - begin init of the PIC
IoWriteByteOnPort(0x20, 0x11);
IoWriteByteOnPort(0xa0, 0x11);
// Set ICW2 (IRQ base offsets)
IoWriteByteOnPort(0x21, 0x20); // 0x20 is the first free interrupt for IRQ0
IoWriteByteOnPort(0xa1, 0x28); // PIC2 is offseted to 0x28
// Set ICW3
IoWriteByteOnPort(0x21, 0x4); // A slave exists
IoWriteByteOnPort(0xa1, 0x2); // You're a slave
// Set ICW4
IoWriteByteOnPort(0x21, 0x1);
IoWriteByteOnPort(0xa1, 0x1);
// Set OCW1 (interrupt masks)
IoWriteByteOnPort(0x21, 0xff);
IoWriteByteOnPort(0xa1, 0xff);
char readIrqs = IoReadByteFromPort(0x21);
IoWriteByteOnPort(0x21, 0xFB & readIrqs); // Enables IRQ forwarding from PIC2 to PIC 1
}
//
// Ends the current interrupt handling
//
void KeSendEOItoPIC(uchar isr)
{
if(isr >= 8)
IoWriteByteOnPort(0xa0,0x20);
IoWriteByteOnPort(0x20,0x20);
}
void KeMaskIRQ(uchar isr)
{
uchar port;
uchar value;
if(isr < 8) {
port = 0x21;
} else {
port = 0xA1;
isr -= 8;
}
value = IoReadByteFromPort(port) | (1 << isr);
IoWriteByteOnPort(port, value);
DebugLog("ISR masked : %d\n", isr);
}
void KeUnmaskIRQ(uchar isr)
{
uchar port;
uchar value;
if(isr < 0x8) {
port = 0x21;
} else {
port = 0xA1;
isr -= 8;
}
value = IoReadByteFromPort(port) & ~(1 << isr);
IoWriteByteOnPort(port, value);
DebugLog("ISR unmasked : %d\n", isr);
}
void KeEnableNMI(void)
{
IoWriteByteOnPort(0x70, IoReadByteFromPort(0x70) & 0x7F);
DebugLog("NMI Interrupts enabled\n");
}
void KeDisableNMI(void)
{
IoWriteByteOnPort(0x70, IoReadByteFromPort(0x70) | 0x80);
DebugLog("NMI Interrupts disabled\n");
}
//
// Get the content of a register of the PIC. Parameter is a ocw3 command :
// - 0x0a : read the IRR
// - 0x0b : read the ISR
//
static inline ushort KeGetIrqRegister(int ocw3)
{
IoWriteByteOnPort(0x20, ocw3);
IoWriteByteOnPort(0xA0, ocw3);
return ((IoReadByteFromPort(0xA0) << 8) | IoReadByteFromPort(0x20)); // We MUST read the COMMAND PORT
}
//
// The main ISR handler
//
void _KeHandleISR(ISRFrame_t *regs)
{
if ((regs->intNo >= 0x15) && (regs->intNo <= 0x1D))
return; // INTEL RESERVED
if ((regs->intNo == 0x0F) || (regs->intNo == 0x1F))
return; // INTEL RESERVED
// Spurious interrupt handling.
if (!(KeGetIrqRegister(0x0b) & (1<<(regs->intNo - 0x20)))) {
KeSpuriousCount++;
return;
}
for (int i = 0; i < isrList.n; i++) {
if (regs->intNo == isrList.entry[i].isrNo) {
isrList.entry[i].isr(regs);
return;
}
}
bprintf(BStdDbg, "[%d]\tISR 0x%x %s\n",
KeGetTicks(),
regs->intNo,
"Unknown ISR Exception");
KeSendEOItoPIC(regs->intNo);
}
//
// Early CPU Exception handler
//
static void EarlyExceptionHandler(ISRFrame_t *regs)
{
bprintf(BStdOut, "\n\n%CPANIC\n[ISR 0x%x] Irrecoverable Kernel %s\n\n"
" Error code : 0x%x (%b)",
VGA_COLOR_LIGHT_RED,
regs->intNo,
ExceptionsChar[regs->intNo],
regs->ErrorCode,
regs->ErrorCode
);
KeBrkDumpRegisters(regs);
BStdOut->flusher(BStdOut);
KeHaltCPU();
}
//
// Double Fault handling and stack overflow detection
//
static void DoubleFaultHandler(ISRFrame_t *regs)
{
bprintf(BStdOut,
"\n\n%CPANIC\n[ISR 0x8] Irrecoverable Kernel Double Fault Abort\n\n"
" Error code : 0x%x (%b)",
VGA_COLOR_LIGHT_RED,
regs->ErrorCode,
regs->ErrorCode
);
KeBrkDumpRegisters(regs);
BStdOut->flusher(BStdOut);
KeHaltCPU();
}
void KeBrkDumpRegisters(ISRFrame_t *regs)
{
IoDoBeepNoIdt();
bprintf(BStdOut, "\n\n"
"%C RIP: %#016lx RSP: %#016lx RBP: %#016lx\n\n"
" SS: %#016lx CS: %#016lx CR0: %#016lx\n"
" CR2: %#016lx CR3: %#016lx CR4: %#016lx\n"
" CR8: %#016lx EFE: %#016lx \n\n"
" RAX: %#016lx RBX: %#016lx RCX: %#016lx\n"
" RDX: %#016lx RSI: %#016lx RDI: %#016lx\n"
" R8: %#016lx R9: %#016lx R10: %#016lx\n"
" R11: %#016lx R12: %#016lx R13: %#016lx\n"
" R14: %#016lx R15: %#016lx \n\n"
" RFLAGS: %#022b (%#06x)",
VGA_COLOR_LIGHT_RED,
regs->rip,
regs->rsp,
regs->rbp,
regs->ss,
regs->cs,
regs->cr0,
regs->cr2,
regs->cr3,
regs->cr4,
regs->cr8,
regs->efer,
regs->rax,
regs->rbx,
regs->rcx,
regs->rdx,
regs->rsi,
regs->rdi,
regs->r8,
regs->r9,
regs->r10,
regs->r11,
regs->r12,
regs->r13,
regs->r14,
regs->r15,
regs->rflags,
regs->rflags
);
BStdOut->flusher(BStdOut);
}