syscalls needed for doom (tell/eof/draw_fb) + minor fixes, compiler shut up etc

2026-05-10 21:25:41 +02:00
parent 22f20d47ad
commit 18ab2c7628
12 changed files with 507 additions and 169 deletions
@@ -1,160 +0,0 @@
-/*
- * @author  xamidev <xamidev@riseup.net>
- * @brief   System call handling
- * @license GPL-3.0-only
- */
-
-#include "config.h"
-#include "sched/scheduler.h"
-#include <arch/x86.h>
-#include <kernel.h>
-#include <stddef.h>
-#include <io/term/term.h>
-#include <sched/process.h>
-#include <io/kbd/ps2.h>
-#include <fs/initfs.h>
-#include <string/string.h>
-
-extern struct process* current_process;
-
-// Return fd on success, -errno on error
-int sys_open(const char* filename, int flags)
-{
-    if (tar_exists(filename) < 0) {
-        return -ENOENT; // file doesn't exist..
-    }
-    // file exists here!
-    if (current_process->next_free_fd >= FDT_MAX) {
-        return -EMFILE;
-    }
-    int fd = current_process->next_free_fd++;
-    current_process->fdt[fd].fd = fd;
-    current_process->fdt[fd].open = true;
-    current_process->fdt[fd].cursor = 0;
-    strncpy(current_process->fdt[fd].filename, filename, PROCESS_NAME_MAX - 1);
-    return fd;
-}
-
-// Return 0 on success, -EBADFD if invalid FD
-int sys_close(int fd)
-{
-    if (fd < 0 || fd >= FDT_MAX) {
-        return -EBADFD;
-    }
-
-    if (!current_process->fdt[fd].open) {
-        return -EBADFD; // FD not opened in the first place
-    }
-
-    current_process->fdt[fd].open = false;
-    current_process->fdt[fd].filename[0] = '\0';
-    current_process->fdt[fd].cursor = 0;
-    return 0;
-}
-
-// Should return the number of bytes read
-int sys_read(unsigned int fd, char* buf, size_t count)
-{
-    size_t i;
-    switch (fd) {
-        case 0: //read from stdin (keyboard)
-            for (i=0; i<count; i++) {
-                buf[i] = keyboard_getchar();
-            }
-            return i;
-        case 1: // from stdout
-        case 2: // from stderr
-            return -EBADFD;
-        default: // from an open file?
-            if (current_process->fdt[fd].open == false) {
-                return -EBADFD; // File descriptor wasn't open
-            }
-            // Here fd refers to a valid opened file..
-            int sz = tar_read(current_process->fdt[fd].filename, buf, count,
-                            current_process->fdt[fd].cursor);
-            if (sz == 0) {
-                return -ENOENT;
-            } else {
-                current_process->fdt[fd].cursor += sz;
-                return sz;
-            }
-    }
-
-    return -EBADFD;
-}
-
-// TODO: Should have a return value: number of bytes written on success, -1 on error (errno set) 
-int sys_write(unsigned int fd, const char* buf, size_t count)
-{
-    switch (fd) {
-        case 1: //stdout
-        case 2: //stderr
-            for (size_t i=0; i<count; i++) {
-                internal_putc(buf[i], NULL);
-            }
-            return count;
-        default:
-            return -EBADFD;
-    }
-}
-
-int sys_exit(int error_code)
-{
-    current_process->status = DEAD;
-    DEBUG("(pid=%u, name=%s)", current_process->pid, current_process->name);
-    return error_code;
-}
-
-/*
- * syscall_handler - System call dispatcher
- * @regs: CPU state
- *
- * This function is called from the interrupt dispatcher,
- * when an interrupt 0x80 is emitted from userland.
- *
- * It switches control to the syscall number provided
- * in %rax. 
- *
- * We try to follow the System V convention here:
- * - syscall number in %rax
- * - args in %rdi, %rsi, %rdx, %r10, %r8, %r9
- * - return value (if any) in %rax
- *
- * Return:
- * <regs> - CPU state after system call
- */
-struct cpu_status* syscall_handler(struct cpu_status* regs)
-{
-    switch (regs->rax)
-    {
-        case 0:
-            DEBUG("sys_read(fd=%u, buf=%p, count=%u)", regs->rdi, regs->rsi, regs->rdx);
-            regs->rax = sys_read(regs->rdi, (char*)regs->rsi, regs->rdx);
-            break;
-        case 1:
-            DEBUG("sys_write(fd=%u, buf=%p, count=%u)", regs->rdi, regs->rsi, regs->rdx);
-            regs->rax = sys_write(regs->rdi, (char*)regs->rsi, regs->rdx);
-            break;
-        case 2:
-            DEBUG("sys_open(filename=%s, flags=%u)", regs->rdi, regs->rsi);
-            regs->rax = sys_open((const char*)regs->rdi, regs->rsi);
-            break;
-        case 3:
-            DEBUG("sys_close(fd=%u)", regs->rdi);
-            regs->rax = sys_close(regs->rdi);
-            break;
-        case 60:
-            DEBUG("sys_exit(error_code=%d)", regs->rdi);
-            regs->rax = sys_exit(regs->rdi);
-            break;
-        default:
-            DEBUG("Bad syscall! (rax=%p, rdi=%p, rsi=%p, rdx=%p)",
-                    regs->rax, regs->rdi, regs->rsi, regs->rdx);
-            regs->rax = 0xbad515ca11;
-            break;
-    }
-
-    DEBUG("returned rax=%p (%u)", regs->rax, regs->rax);
-
-    return regs;
-}