feat: some refactors

kernel/kernel.c

@@ -11,22 +11,111 @@
 #include <kprint.h>
 #include <libc/readline.h>
 #include <libc/string.h>
+#include <libk.h>
+
+#define BOOTLOADER_NAME_MAX_LENGTH 64
+#define CMDLINE_MAX_LENGTH 256
 
 const char *msg_booted = "Booted Successfully!\n";
 const char *newline = "\n";
 const char *msg_unknown_command = "Unknown command: ";
 
-const char *cmd_echo = "echo";
-const char *cmd_print_mmap = "print_mmap";
-const char *cmd_print_malloc = "print_malloc";
-const char *cmd_print_tick = "print_tick";
+char bootloader_name[BOOTLOADER_NAME_MAX_LENGTH];
+char cmdline[CMDLINE_MAX_LENGTH];
+
+typedef void (*cmd_handler_func)(const char *);
+
+typedef struct {
+    char *cmd;
+    cmd_handler_func handler;
+} cmd_handler;
+
+void print(const char *arg);
+void echo(const char *arg);
+void help(const char *arg);
+
+cmd_handler cmd_handlers[] = {
+        {"help", help},
+        {"echo", echo},
+        {"print", print},
+        {NULL,   NULL},
+};
+
+void print_bootinfo() {
+    kprint("Bootloader name: ");
+    kprint(bootloader_name[0] == 0 ? "NULL" : bootloader_name);
+    kprint(newline);
+    kprint("cmdline: ");
+    kprint(cmdline[0] == 0 ? "NULL" : cmdline);
+    kprint(newline);
+}
+
+void help(const char* arg) {
+    kprint("Available commands:\n");
+    int index = 0;
+    while (true) {
+        if (cmd_handlers[index].cmd == NULL) {
+            break;
+        }
+        kprint(cmd_handlers[index].cmd);
+        kprint(newline);
+        index += 1;
+    }
+
+}
+
+void echo(const char *arg) {
+    kprint(arg);
+    kprint(newline);
+}
+
+void print(const char *arg) {
+    if (strcmp(arg, "mmap") == 0) {
+        print_mmap_info();
+    } else if (strcmp(arg, "malloc") == 0) {
+        print_malloc_info();
+    } else if (strcmp(arg, "tick") == 0) {
+        print_current_tick();
+    } else if (strcmp(arg, "bootinfo") == 0) {
+        print_bootinfo();
+    } else {
+        kprint("Unknown print ");
+        kprint(arg);
+        kprint(newline);
+    }
+}
 
 void main_loop();
 
-void panic() {
-    kprint("PANIC!");
-    asm("cli;"
-        "hlt;");
+void store_bootloader_info(multiboot_info_t *multiboot_info) {
+    // get bootloader and cmdline
+    if (multiboot_info->flags & MULTIBOOT_INFO_CMDLINE) {
+        int cmdline_length = strlen((const char *) multiboot_info->cmdline);
+        if (cmdline_length > CMDLINE_MAX_LENGTH) {
+            kprint("cmdline to long!");
+            k_panic();
+        }
+        memcpy(cmdline, (char *) multiboot_info->cmdline, cmdline_length);
+    }
+    if (multiboot_info->flags & MULTIBOOT_INFO_BOOT_LOADER_NAME) {
+        int bootloader_length = strlen((const char *) multiboot_info->boot_loader_name);
+        if (bootloader_length > BOOTLOADER_NAME_MAX_LENGTH) {
+            kprint("bootloader name to long!");
+            k_panic();
+        }
+        memcpy(bootloader_name, (char *) multiboot_info->boot_loader_name, bootloader_length);
+    }
+}
+
+void init_mmap(multiboot_info_t *multiboot_info) {
+    if (multiboot_info->flags & (1 << 6)) {
+        init_mmap_multiboot((struct multiboot_mmap_entry *) multiboot_info->mmap_addr,
+                            multiboot_info->mmap_length / sizeof(struct multiboot_mmap_entry));
+        // todo fallback on other mechanisms?
+    } else {
+        kprint("mmap invalid!\n");
+        k_panic();
+    }
 }
 
 void kmain(multiboot_info_t *multiboot_info) {
@@ -36,66 +125,43 @@ void kmain(multiboot_info_t *multiboot_info) {
     kprint_register(vga_kprint);
     serial_init();
     kprint_register(serial_kprint);
-    if (multiboot_info->flags & (1 << 6)) {
-        kprint("mmap valid\n");
-        init_mmap((struct multiboot_mmap_entry *) multiboot_info->mmap_addr,
-                  multiboot_info->mmap_length / sizeof(struct multiboot_mmap_entry));
-    } else {
-        kprint("mmap invalid!\n");
-        panic();
-    }
 
-//    vga_print_string(msg_booted, VGA_WHITE | (VGA_DARK_GRAY << VGA_SHIFT_BG));
+    store_bootloader_info(multiboot_info);
+    init_mmap(multiboot_info);
+
     kprint(msg_booted);
-    kprint((char *) multiboot_info->boot_loader_name);
     kprint(newline);
-//    multiboot_memory_map_t *fe = multiboot_info->mmap_addr;
-//    port_byte_out(0x3d4, 14);
-//    int pos = port_byte_in(0x3d5);
-//    pos <<= 8;
-//
-//    port_byte_out(0x3d4, 15);
-//    pos += port_byte_in(0x3d5);
 
-    asm volatile("sti");
+    // init done, enable interrupts
+    __asm__ __volatile__("sti");
+    // init timer for future task switching
     init_timer(50);
+    // setup PS/2 keyboard
     init_keyboard();
 
-//    print_mmap_info();
+    // enter main loop
     while (true) {
         main_loop();
     }
-
-//    vga_set_raw(pos * 2, 'X');
-//    vga_set_raw(pos * 2 + 1, 0xf);
-    do {} while (1);
 }
 
 void main_loop() {
     char *msg = readline(NULL);
     char *args = strchr(msg, ' ') + 1;
     args[-1] = 0;
-    if (strcmp(cmd_echo, msg) == 0) {
-        kprint(args);
-        kprint(newline);
-        goto _main_loop_end;
+    int test_index = 0;
+    while (true) {
+        if (cmd_handlers[test_index].cmd == 0) {
+            kprint(msg_unknown_command);
+            kprint(msg);
+            kprint(newline);
+            break;
+        }
+        if (strcmp(cmd_handlers[test_index].cmd, msg) == 0) {
+            cmd_handlers[test_index].handler(args);
+            break;
+        }
+        test_index++;
     }
-    if (strcmp(cmd_print_mmap, msg) == 0) {
-        print_mmap_info();
-        goto _main_loop_end;
-    }
-    if (strcmp(cmd_print_malloc, msg) == 0) {
-        print_malloc_info();
-        goto _main_loop_end;
-    }
-    if (strcmp(cmd_print_tick, msg) == 0) {
-        print_current_tick();
-        goto _main_loop_end;
-    }
-
-    kprint(msg_unknown_command);
-    kprint(msg);
-    kprint(newline);
-    _main_loop_end:
     free(msg);
 }