feat: basic ksh

kernel/src/core/string.c

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright (c) 2025 0xKarinyash
+
+#include <core/string.h>
+
+i32 strcmp(const char* s1, const char* s2) {
+    while (*s1 && (*s1 == *s2)) {
+        s1++;
+        s2++;
+    }
+    return *(const unsigned char*)s1 - *(const unsigned char*)s2;
+}

kernel/src/drivers/console.c

@@ -43,6 +43,10 @@ void console_init(SG_Context *ctx) {
     s_font.base = (const unsigned char*)font8x16;
 }
 
+u64 console_get_colors() {
+    return ((u64) s_color << 32) | s_bg_color;
+}
+
 void console_clear(u32 color) {
     if (!ctx_ptr) return;
 

kernel/src/kmain.c

@@ -3,6 +3,7 @@
 
 #include "bootinfo.h"
 #include "../data/logo.h"
+#include "shell/ksh.h"
 
 #include <types.h>
 
@@ -10,6 +11,8 @@
 #include <drivers/serial.h>
 #include <drivers/console.h>
 
+#include <core/panic.h>
+
 #include <gdt.h>
 #include <idt.h>
 #include <pic.h>
@@ -49,12 +52,7 @@ void kmain(Bootinfo* info) {
     SG_Point text_normal_point = {0, 120};  // not nice to hardcode nums like that but we have what we have
     console_set_cursor_pos(&text_normal_point);
 
-    kprintf("ksh_> ");
-    char buff[32];
-    kgets(buff, 32);
-    kprintf("You typed: %s", buff);
-
-    __asm__ volatile ("sti");
-
-    while (1) { __asm__("hlt"); }
+    ksh();
+    
+    panic("Kernel main loop exited");
 }

kernel/src/shell/ksh.c

@@ -1,3 +1,58 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 // Copyright (c) 2025 0xKarinyash
+#include <shell/ksh.h>
+#include <drivers/console.h>
+#include <core/string.h>
 
+typedef enum {
+    TOKEN_NULL,
+    TOKEN_ILLEGAL,
+    
+    TOKEN_HELP,
+
+    TOKEN_QUIT,
+    TOKEN_CLEAR
+} ksh_token;
+
+typedef struct {
+    char* str;
+    ksh_token token;
+} ksh_command_map;
+
+static const ksh_command_map token_map[] = {
+    {"q", TOKEN_QUIT},
+    {"quit", TOKEN_QUIT},
+    {"exit", TOKEN_QUIT},
+    
+    {"cls", TOKEN_CLEAR},
+    {"clear", TOKEN_CLEAR},
+
+    {"help", TOKEN_HELP},
+    {nullptr, TOKEN_NULL}
+};
+
+ksh_token char2token(char* token) {
+    for (i32 i = 0; token_map[i].str != nullptr; i++) {
+        if (strcmp(token, token_map[i].str) == 0) return token_map[i].token;
+    }
+    return TOKEN_ILLEGAL;
+}
+
+static void print_help() {
+    kprintf("\tWelcome to ^ptermOS^0's kernel shell!\n");
+    kprintf("\tIt can almost nothing! yet.");
+}
+
+void ksh() {
+    while (true) {
+        kprintf("\nksh_> ");
+        char cmdbuff[256];
+        kgets(cmdbuff, 256);
+        switch(char2token(cmdbuff)) {
+            case TOKEN_QUIT: return; // that'll cause panic lol
+            case TOKEN_CLEAR: console_clear((u32) console_get_colors() & 0xFFFFFFFF); break;
+            case TOKEN_HELP: print_help(); break;
+            default: kprintf("Unknown command!!"); break;
+        }
+    }
+}