104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
#include <stdint.h>
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#include <stddef.h>
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#include "memory/mm.h"
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#include "process.h"
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#include "scheduler.h"
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#include "kbd.h"
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#include <drivers/vga/vga.h>
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#include <lib/print.h>
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static int32_t sys_exit(int status) {
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process_t* task = current_task();
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task->state = STATE_DEAD;
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kprintf("Process %d exited with status %d\n", task->pid, status);
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exit();
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return 0;
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}
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static int32_t sys_write(int fd, const void* buf, size_t count) {
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if (fd == 1 || fd == 2) { // stdout or stderr
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const char* cbuf = (const char*)buf;
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for (size_t i = 0; i < count; i++) {
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vga_putchar(cbuf[i]);
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}
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return count;
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}
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return -1;
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}
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static int32_t sys_read(int fd, void* buf, size_t count) {
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if (fd == 0) {
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char* cbuf = (char*)buf;
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size_t bytes_read = 0;
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while (bytes_read < count) {
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kbd_wait();
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if (kbd_ready()) {
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char c = kbd_read();
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cbuf[bytes_read++] = c;
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if (c == '\n') break;
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}
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}
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return bytes_read;
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}
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return -1;
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}
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static int32_t sys_open(const char* filename, int flags) {
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return -1;
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}
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static int32_t sys_close(int fd) {
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return -1;
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}
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static int32_t sys_brk(uint32_t new_break) {
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process_t* current = current_task();
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if (new_break == 0) {
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return current->heap_end;
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}
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if (new_break < current->heap_end) {
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current->heap_end = new_break;
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return current->heap_end;
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}
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uint32_t page_start = (current->heap_end + 4095) & ~4095;
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uint32_t page_end = (new_break + 4095) & ~4095;
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for (uint32_t addr = page_start; addr < page_end; addr += 4096) {
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// 1. Allocate a physical frame using your PMM (Physical Memory Manager)
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void* phys = p_alloc_frame();
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// 2. Map it into the current page directory using your VMM (Virtual Memory Manager)
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map_page(addr, (uint32_t)phys, PAGE_PRESENT | PAGE_WRITABLE | PAGE_USER);
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}
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current->heap_end = new_break;
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return current->heap_end;
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}
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typedef struct registers {
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uint32_t gs, fs, es, ds; // Pushed manually
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uint32_t edi, esi, ebp, esp, ebx, edx, ecx, eax; // Pushed by pusha
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uint32_t int_no, err_code; // Pushed manually
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uint32_t eip, cs, eflags, useresp, ss; // Pushed automatically by CPU
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} registers_t;
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int32_t syscall(registers_t* regs) {
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switch(regs->eax) {
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case 1: return sys_exit(regs->ebx);
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case 3: return sys_read(regs->ebx, (void*)regs->ecx, regs->edx);
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case 4: return sys_write(regs->ebx, (const void*)regs->ecx, regs->edx);
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case 5: return sys_open((const char*)regs->ebx, regs->ecx);
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case 6: return sys_close(regs->ebx);
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case 12: return sys_brk(regs->ebx);
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default:
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return -1;
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}
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} |