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sortix--sortix/sortix/interrupt.cpp
Jonas 'Sortie' Termansen 2afe9d1fd6 Implemented the fork() system call and what it needed to work properly.
This commit got completely out of control.

Added the fork(), getpid(), getppid(), sleep(), usleep() system calls, and
aliases in the Maxsi:: namespace.

Fixed a bug where zero-byte allocation would fail.

Worked on the DescriptorTable class which now works and can fork.

Got rid of some massive print-registers statements and replaced them with
the portable InterruptRegisters::LogRegisters() function.

Removed the SysExecuteOld function and replaced it with Process::Execute().

Rewrote the boot sequence in kernel.cpp such that it now loads the system
idle process 'idle' as PID 0, and the initization process 'init' as PID 1.

Rewrote the SIGINT hack.

Processes now maintain a family-tree structure and keep track of their
threads. PIDs are now allocated using a simple hack. Virtual memory
per-process can now be allocated using a simple hack. Processes can now be
forked. Fixed the Process::Execute function such that it now resets the
stack pointer to where the stack actually is - not just a magic value.
Removed the old and ugly Process::_endcodesection hack.

Rewrote the scheduler into a much cleaner and faster version. Debug code is
now moved to designated functions. The noop kernel-thread has been replaced
by a simple user-space infinite-loop program 'idle'.

The Thread class has been seperated from the Scheduler except in Scheduler-
related code. Thread::{Save,Load}Registers has been improved and has been
moved to $(CPU)/thread.cpp. Threads can now be forked. A new CreateThread
function creates threads properly and portably.

Added a MicrosecondsSinceBoot() function.

Fixed a crucial bug in MemoryManagement::Fork().

Added an 'idle' user-space program that is a noop infinite loop, which is
used by the scheduler when there is nothing to do.

Rewrote the 'init' program such that it now forks off a shell, instead of
becoming the shell.

Added the $$ (current PID) and $PPID (parent PPID) variables to the shell.
2011-11-01 01:00:20 +01:00

135 lines
4.1 KiB
C++

/******************************************************************************
COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
This file is part of Sortix.
Sortix 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 (at your option) any later
version.
Sortix 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 Sortix. If not, see <http://www.gnu.org/licenses/>.
interrupt.cpp
High level interrupt service routines and interrupt request handlers.
******************************************************************************/
#include "platform.h"
#include "log.h"
#include "interrupt.h"
#include "panic.h"
#include "process.h" // Hack for SIGSEGV
#include "sound.h" // Hack for SIGSEGV
namespace Sortix
{
namespace Interrupt
{
const bool DEBUG_EXCEPTION = false;
const bool DEBUG_IRQ = false;
size_t numknownexceptions = 20;
const char* exceptions[] =
{ "Divide by zero", "Debug", "Non maskable interrupt", "Breakpoint",
"Into detected overflow", "Out of bounds", "Invalid opcode",
"No coprocessor", "Double fault", "Coprocessor segment overrun",
"Bad TSS", "Segment not present", "Stack fault",
"General protection fault", "Page fault", "Unknown interrupt",
"Coprocessor fault", "Alignment check", "Machine check",
"SIMD Floating-Point" };
Handler interrupthandlers[256];
void RegisterHandler(uint8_t n, Interrupt::Handler handler)
{
interrupthandlers[n] = handler;
}
// This gets called from our ASM interrupt handler stub.
extern "C" void ISRHandler(Sortix::CPU::InterruptRegisters* regs)
{
#ifdef PLATFORM_X86
if ( regs->int_no < 32 )
{
const char* message = ( regs->int_no < numknownexceptions )
? exceptions[regs->int_no] : "Unknown";
if ( DEBUG_EXCEPTION ) { regs->LogRegisters(); Log::Print("\n"); }
// Halt and catch fire if we are the kernel.
if ( (regs->cs & (0x4-1)) == 0 )
{
PanicF("Unhandled CPU Exception id %zu '%s' at eip=0x%zx "
"(cr2=0x%p, err_code=0x%p)", regs->int_no, message,
regs->eip, regs->cr2, regs->err_code);
}
Log::Print("The current program has crashed and was terminated:\n");
Log::PrintF("%s exception at eip=0x%zx (cr2=0x%p, err_code=0x%p)\n",
message, regs->eip, regs->cr2, regs->err_code);
Sound::Mute();
const char* programname = "sh";
Process::Execute(programname, regs);
return;
}
if ( interrupthandlers[regs->int_no] != NULL )
{
interrupthandlers[regs->int_no](regs);
}
#else
#warning "ISR handlers are not supported on this arch"
while(true);
#endif
}
// This gets called from our ASM interrupt handler stub.
extern "C" void IRQHandler(Sortix::CPU::InterruptRegisters* regs)
{
#ifdef PLATFORM_X86
// TODO! IRQ 7 and 15 might be spurious and might need to be ignored.
// See http://wiki.osdev.org/PIC for details (section Spurious IRQs).
if ( regs->int_no == 32 + 7 || regs->int_no == 32 + 15 ) { return; }
if ( DEBUG_IRQ )
{
Log::PrintF("IRQ%u ", regs->int_no-32);
regs->LogRegisters();
Log::Print("\n");
}
if ( regs->int_no < 32 || 48 < regs->int_no )
{
PanicF("IRQ eax=%u, int_no=%u, err_code=%u, eip=%u!",
regs->eax, regs->int_no, regs->err_code, regs->eip);
}
// Send an EOI (end of interrupt) signal to the PICs.
// Send reset signal to slave if this interrupt involved the slave.
if (regs->int_no >= 40) { X86::OutPortB(0xA0, 0x20); }
// Send reset signal to master.
X86::OutPortB(0x20, 0x20);
if ( interrupthandlers[regs->int_no] != NULL )
{
interrupthandlers[regs->int_no](regs);
}
#else
#warning "IRQ handlers are not supported on this arch"
while(true);
#endif
}
}
}