change vga_printk definitions

include/kernel/vga.h

@@ -14,6 +14,6 @@ struct vga_char {
 #define VGA_SCREEN_HEIGHT_IN_CHARS (25U)
 
 void vga_put_char(struct vga_char* c);
-void vga_printk(const int8_t* str, uint8_t color);
+void vga_printk(const char* str, uint8_t color);
 
 #endif // _KERNEL_VGA_H_

src/kernel/vga.c

@@ -19,7 +19,7 @@ void vga_new_line()
     p_vga_head += (VGA_SCREEN_WIDTH_IN_CHARS - offset);
 }
 
-void vga_printk(const int8_t* str, uint8_t color)
+void vga_printk(const char* str, uint8_t color)
 {
     struct vga_char s_c;
     s_c.color = color;

src/kernel_main.c

@@ -13,9 +13,9 @@ void kernel_main(void)
     result = check_a20_on();
 
     if (result) {
-        vga_printk((const int8_t*)"A20 is ON\n", 0x0fU);
+        vga_printk("A20 is ON\n", 0x0fU);
     } else {
-        vga_printk((const int8_t*)"A20 is NOT ON\n", 0x0fU);
+        vga_printk("A20 is NOT ON\n", 0x0fU);
     }
 
     uint32_t mem_size = 0;
@@ -26,9 +26,9 @@ void kernel_main(void)
     snprintf(buf, 128, "Memory size: %d bytes (%d MB), 16k blocks: %d, 64k blocks: %d\n",
         mem_size, mem_size / 1024 / 1024, (int32_t)asm_mem_size_info.n_1k_blks,
         (int32_t)asm_mem_size_info.n_64k_blks);
-    vga_printk((const int8_t*)buf, 0x0fu);
+    vga_printk(buf, 0x0fu);
 
-    vga_printk((const int8_t*)"No work to do, halting...\n", 0x0fU);
+    vga_printk("No work to do, halting...\n", 0x0fU);
 
 _loop:
     asm("hlt");