93 lines
2.0 KiB
C++
93 lines
2.0 KiB
C++
#include "apic.h"
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#include "console.h"
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#include "cpu.h"
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#include "gdt.h"
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#include "interrupts.h"
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#include "log.h"
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#include "scheduler.h"
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scheduler scheduler::s_instance(nullptr);
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static const uint32_t quantum = 5000000;
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const int stack_size = 0x1000;
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char taskAstack[stack_size];
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char taskBstack[stack_size];
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uint64_t taskAcount = 0;
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void taskA()
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{
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console *cons = console::get();
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while(1) {
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cons->putc('.');
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}
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}
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void taskB()
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{
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console *cons = console::get();
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while(1) {
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cons->putc('+');
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}
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}
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scheduler::scheduler(lapic *apic) :
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m_apic(apic),
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m_current(0)
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{
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m_processes.ensure_capacity(50);
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}
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static process
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create_process(uint16_t pid, void *stack, void (*rip)())
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{
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uint64_t flags;
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__asm__ __volatile__ ( "pushf; pop %0" : "=r" (flags) );
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// This is a hack for now, until we get a lot more set up.
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// I just want to see task switching working inside ring0 first
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uint16_t kcs = (1 << 3) | 0;
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uint16_t cs = (3 << 3) | 3;
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uint16_t kss = (2 << 3) | 0;
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uint16_t ss = (4 << 3) | 3;
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void *sp = kutil::offset_pointer(stack, stack_size);
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cpu_state *state = reinterpret_cast<cpu_state *>(sp) - 1;
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kutil::memset(state, 0, sizeof(cpu_state));
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state->ds = state->ss = kss;
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state->cs = kcs;
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state->rflags = 0x202;
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state->user_rsp = reinterpret_cast<uint64_t>(sp);
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state->rip = reinterpret_cast<uint64_t>(rip);
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log::debug(logs::task, "Creating a user RSP of %016lx", state->user_rsp);
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return {pid, reinterpret_cast<addr_t>(state)};
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}
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void
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scheduler::start()
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{
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m_apic->enable_timer(isr::isrTimer, 128, quantum, false);
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m_processes.append({0, 0}); // The kernel idle task
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m_processes.append(create_process(1, &taskAstack[0], &taskA));
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m_processes.append(create_process(2, &taskBstack[0], &taskB));
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}
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addr_t
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scheduler::tick(addr_t rsp0)
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{
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log::debug(logs::task, "Scheduler tick.");
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m_processes[m_current].rsp = rsp0;
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m_current = (m_current + 1) % m_processes.count();
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rsp0 = m_processes[m_current].rsp;
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tss_set_stack(0, rsp0);
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m_apic->reset_timer(quantum);
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return rsp0;
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}
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