mirror of
https://github.com/SerenityOS/serenity
synced 2024-09-16 06:30:41 +00:00
018da1be11
Add a separate lock to protect the VFS. I think this might be a good idea. I'm not sure it's a good approach though. I'll fiddle with it as I go along. It's really fun to figure out all these things on my own.
155 lines
3.6 KiB
C++
155 lines
3.6 KiB
C++
#include "i8253.h"
|
|
#include "i386.h"
|
|
#include "IO.h"
|
|
#include "VGA.h"
|
|
#include "Task.h"
|
|
#include "system.h"
|
|
#include "PIC.h"
|
|
|
|
#define IRQ_TIMER 0
|
|
|
|
extern "C" void tick_ISR();
|
|
extern "C" void clock_handle();
|
|
|
|
extern volatile DWORD state_dump;
|
|
|
|
asm(
|
|
".globl tick_ISR \n"
|
|
".globl state_dump \n"
|
|
"state_dump: \n"
|
|
".long 0\n"
|
|
"tick_ISR: \n"
|
|
" pusha\n"
|
|
" pushw %ds\n"
|
|
" pushw %es\n"
|
|
" pushw %fs\n"
|
|
" pushw %gs\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" pushw %ss\n"
|
|
" popw %ds\n"
|
|
" popw %es\n"
|
|
" popw %fs\n"
|
|
" popw %gs\n"
|
|
" mov %esp, state_dump\n"
|
|
" call clock_handle\n"
|
|
" popw %gs\n"
|
|
" popw %gs\n"
|
|
" popw %fs\n"
|
|
" popw %es\n"
|
|
" popw %ds\n"
|
|
" popa\n"
|
|
" iret\n"
|
|
);
|
|
|
|
/* Timer related ports */
|
|
#define TIMER0_CTL 0x40
|
|
#define TIMER1_CTL 0x41
|
|
#define TIMER2_CTL 0x42
|
|
#define PIT_CTL 0x43
|
|
|
|
/* Building blocks for PIT_CTL */
|
|
#define TIMER0_SELECT 0x00
|
|
#define TIMER1_SELECT 0x40
|
|
#define TIMER2_SELECT 0x80
|
|
|
|
#define MODE_COUNTDOWN 0x00
|
|
#define MODE_ONESHOT 0x02
|
|
#define MODE_RATE 0x04
|
|
#define MODE_SQUARE_WAVE 0x06
|
|
|
|
#define WRITE_WORD 0x30
|
|
|
|
/* Miscellaneous */
|
|
#define BASE_FREQUENCY 1193182
|
|
|
|
void clock_handle()
|
|
{
|
|
IRQHandlerScope scope(IRQ_TIMER);
|
|
|
|
if (!current)
|
|
return;
|
|
|
|
system.uptime++;
|
|
|
|
if (current->tick())
|
|
return;
|
|
|
|
//return;
|
|
|
|
auto& regs = *reinterpret_cast<RegisterDump*>(state_dump);
|
|
current->tss().gs = regs.gs;
|
|
current->tss().fs = regs.fs;
|
|
current->tss().es = regs.es;
|
|
current->tss().ds = regs.ds;
|
|
current->tss().edi = regs.edi;
|
|
current->tss().esi = regs.esi;
|
|
current->tss().ebp = regs.ebp;
|
|
current->tss().ebx = regs.ebx;
|
|
current->tss().edx = regs.edx;
|
|
current->tss().ecx = regs.ecx;
|
|
current->tss().eax = regs.eax;
|
|
current->tss().eip = regs.eip;
|
|
current->tss().cs = regs.cs;
|
|
current->tss().eflags = regs.eflags;
|
|
|
|
// Compute task ESP.
|
|
// Add 12 for CS, EIP, EFLAGS (interrupt mechanic)
|
|
|
|
// FIXME: Hmm. Should we add an extra 8 here for SS:ESP in some cases?
|
|
// If this IRQ occurred while in a user task, wouldn't that also push the stack ptr?
|
|
current->tss().esp = regs.esp + 12;
|
|
|
|
current->tss().ss = regs.ss;
|
|
|
|
if ((current->tss().cs & 3) != 0) {
|
|
#if 0
|
|
kprintf("clock'ed across to ring0\n");
|
|
kprintf("code: %w:%x\n", current->tss().cs, current->tss().eip);
|
|
kprintf(" stk: %w:%x\n", current->tss().ss, current->tss().esp);
|
|
kprintf("astk: %w:%x\n", regs.ss_if_crossRing, regs.esp_if_crossRing);
|
|
//HANG;
|
|
#endif
|
|
current->tss().ss = regs.ss_if_crossRing;
|
|
current->tss().esp = regs.esp_if_crossRing;
|
|
}
|
|
|
|
// Prepare a new task to run;
|
|
if (!scheduleNewTask())
|
|
return;
|
|
Task::prepForIRETToNewTask();
|
|
|
|
// Set the NT (nested task) flag.
|
|
asm(
|
|
"pushf\n"
|
|
"orl $0x00004000, (%esp)\n"
|
|
"popf\n"
|
|
);
|
|
}
|
|
|
|
namespace PIT {
|
|
|
|
void initialize()
|
|
{
|
|
WORD timer_reload;
|
|
|
|
IO::out8(PIT_CTL, TIMER0_SELECT | WRITE_WORD | MODE_SQUARE_WAVE);
|
|
|
|
timer_reload = (BASE_FREQUENCY / TICKS_PER_SECOND);
|
|
|
|
/* Send LSB and MSB of timer reload value. */
|
|
|
|
kprintf("PIT(i8253): %u Hz, square wave (%x)\n", TICKS_PER_SECOND, timer_reload);
|
|
|
|
IO::out8(TIMER0_CTL, LSB(timer_reload));
|
|
IO::out8(TIMER0_CTL, MSB(timer_reload));
|
|
|
|
registerInterruptHandler(IRQ_VECTOR_BASE + IRQ_TIMER, tick_ISR);
|
|
|
|
PIC::enable(IRQ_TIMER);
|
|
}
|
|
|
|
}
|