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#include "scheduler.h"
#include <stdlib.h>
void task_a(void) {
while (true) printk("A");
}
void task_b(void) {
while (true) printk("B");
}
static uint8_t stack_a[4096] = {0};
static uint8_t stack_b[4096] = {0};
constexpr uint16_t max_tasks = 2;
static cpu_state_t* tasks[max_tasks];
Scheduler::Scheduler(uint16_t cs) : InterruptHandler(0x00) {
add_task(stack_a, cs, &task_a);
add_task(stack_b, cs, task_b);
}
bool Scheduler::add_task(uint8_t* stack, uint16_t cs, void (*entry)()) {
if (last_task_id == uint16_t_max) return false;
uint16_t id = last_task_id++;
++num_tasks;
cpu_state_t* cpu_state = reinterpret_cast<cpu_state_t*>(stack + 4096 - sizeof(cpu_state_t));
cpu_state->eip = reinterpret_cast<uint32_t>(entry);
cpu_state->cs = cs;
cpu_state->eflags = 0x202;
tasks[id] = cpu_state;
printk("adding task: cs ", uhex{cpu_state->cs}, " stack ", uhex{reinterpret_cast<uint32_t>(tasks[id])}, " entry ",
uhex{cpu_state->eip}, '\n');
return true;
}
cpu_state_t* Scheduler::trigger(cpu_state_t* cpu) {
tasks[current_task] = cpu;
if (++current_task >= num_tasks) current_task %= num_tasks;
// printk("swapped to task ", current_task, '\n');
return tasks[current_task];
}
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