test: paging breaks

anasos-kernel/bootloader/Makefile

@@ -2,7 +2,8 @@ all:
 	nasm -f elf64 header.asm -o header.o
 	nasm -f elf64 boot-64.asm -o boot-64.o
 	nasm -f elf64 boot.asm -o boot.o
+	nasm -f elf64 e820.asm -o e820.o
 
-	ld -m elf_x86_64 -T ../linker.ld -o ../../AnasOS/boot/kernel boot.o boot-64.o header.o
+	ld -m elf_x86_64 -T ../linker.ld -o ../../AnasOS/boot/kernel boot.o boot-64.o header.o #e820.o
 	grub-mkrescue -o AnasOS.iso ../../AnasOS/
 	qemu-system-x86_64 AnasOS.iso

anasos-kernel/bootloader/boot-64.asm

@@ -1,9 +1,9 @@
-GLOBAL long_mode_start 
+GLOBAL start_long_mode 
 EXTERN _start
 
 SECTION .text
 BITS 64
-long_mode_start:
+start_long_mode:
     ; load null to all data segmant registers (needed for the cpu to work as intended)
     ; documented here - https://www.gnu.org/software/grub/manual/multiboot2/multiboot.html#Machine-state
     MOV ax, 0
@@ -13,7 +13,14 @@ long_mode_start:
     MOV gs, ax
     MOV ss, ax
 
-    CALL _start
+    ; CALL _start
+    
+    ; ; Write the letter "W" to the VGA text buffer
+    ; MOV rdi, 0xB8000       ; VGA text buffer address (identity-mapped in page tables)
+    ; MOV ax, 0x0F57         ; "W" (ASCII 0x57) with attribute 0x0F (white on black)
+    ; MOV word [rdi], ax     ; Write the word (character + attribute) to the VGA buffer
+
 
     HLT
 
+

anasos-kernel/bootloader/boot.asm

@@ -10,25 +10,24 @@ GLOBAL PT
 GLOBAL stack_bottom
 GLOBAL stack_top
 
-EXTERN long_mode_start
+EXTERN start_long_mode
 EXTERN save_boot_info
 
 SECTION .text
 BITS 32
 
-start:
-    ; CALL save_boot_info
-
+start_protected_mode:
     MOV esp, stack_top
     CALL check_multiboot
     CALL check_cpuid
     CALL check_long_mode
 
     CALL setup_page_tables
     CALL enable_paging
+    call write_W_to_vga
 
     LGDT [gdt64.pointer]
-    JMP gdt64.code_segment:long_mode_start
+    JMP gdt64.code_segment:start_long_mode
 
     HLT
 
@@ -109,6 +108,11 @@ setup_page_tables:
     CMP ecx, 512            ; Fill all 512 entries (2 MiB)
     JL .loop_setup_first_pt
 
+    ; Ensure VGA buffer (0xB8000) is identity-mapped
+    MOV eax, 0xB8000        ; Physical address of VGA buffer
+    OR eax, 0b11            ; Present, Writable
+    MOV [PT + (0xB8 * 8)], eax ; Map 0xB8000 in the first PT
+
     ; Fill second PT for the next 2 MiB
     MOV ecx, 0
 .loop_setup_second_pt:
@@ -155,6 +159,14 @@ error:
     MOV byte  [0xB800C], al
     HLT
 
+write_W_to_vga:
+    ; Write the letter "W" to the VGA text buffer
+    mov edi, 0xB8000      ; VGA text buffer address
+    mov ax, 0x0F57        ; "W" (ASCII 0x57) with attribute 0x0F (white on black)
+    mov word [edi], ax    ; Write the word (character + attribute) to VGA memory
+    HLT
+    ret                   ; Return to the caller
+
 SECTION .bss
 ALIGN 4096
 start_page_table:

anasos-kernel/linker copy.ld

@@ -0,0 +1,49 @@
+ENTRY(start_protected_mode)
+
+SECTIONS
+{
+    . = 0x0;
+    .boot :
+    {
+        KEEP(*(.multiboot_header));
+        *(.boot)
+    }
+
+    /* Page table addresses already defined in boot.asm, but ensure alignment */
+    . = ALIGN(4096); /* Page size */
+    __page_table_start = .;
+	_p4 = PML4;         /* Reference PML4 address from boot.asm */
+	_p3 = PDPT;         /* Reference PDPT address from boot.asm */
+	_p2 = PD;           /* Reference PD address from boot.asm */
+	_p1 = PT;           /* Reference PT address from boot.asm */
+	__page_table_end = .;
+
+    /* Stack setup handled in boot.asm */
+    _stack_start = stack_bottom; /* Stack defined in boot.asm */
+    _stack_end = stack_top;
+
+    /* Memory map section for bootloader metadata */
+    __bootloader_start = .;
+    _memory_map = .;  /* Memory map entry */
+    . += 4096;		/* Reserve 4KB for memory map */
+
+    /* Kernel metadata section */
+    .kernel :
+    {
+        KEEP(*(.kernel))
+    }
+
+    /* Text section: contains code */
+    .text :
+    {
+        *(.text)
+    }
+
+    .bss ALIGN(4096):
+    {
+        __bss_start = .;
+        *(.bss)
+        *(COMMON)
+        __bss_end = .;
+    }
+}

anasos-kernel/linker.ld

@@ -1,50 +1,17 @@
-ENTRY(start)
+ENTRY(start_protected_mode)
 
 SECTIONS
 {
-    /* Reserve a buffer for kernel loading */
-    . = 0x0;
-    .boot :
-    {
-        KEEP(*(.multiboot_header));
-        *(.boot)
-    }
-
-    /* Page table addresses already defined in boot.asm, but ensure alignment */
-    . = ALIGN(4096); /* Page size */
-    __page_table_start = .;
-	_p4 = PML4;         /* Reference PML4 address from boot.asm */
-	_p3 = PDPT;         /* Reference PDPT address from boot.asm */
-	_p2 = PD;           /* Reference PD address from boot.asm */
-	_p1 = PT;           /* Reference PT address from boot.asm */
-	__page_table_end = .;
-
-    /* Stack setup handled in boot.asm */
-    _stack_start = stack_bottom; /* Stack defined in boot.asm */
-    _stack_end = stack_top;
+	. = 1M;
 
-    /* Memory map section for bootloader metadata */
-    __bootloader_start = .;
-    _memory_map = .;  /* Memory map entry */
-    . += 4096;		/* Reserve 4KB for memory map */
-
-    /* Kernel metadata section */
-    .kernel :
-    {
-        KEEP(*(.kernel))
-    }
-
-    /* Text section: contains code */
-    .text :
-    {
-        *(.text)
-    }
+	.boot :
+	{
+		KEEP(*(.multiboot_header))
+        *(.boot)
+	}
 
-    .bss ALIGN(4096):
-    {
-        __bss_start = .;
-        *(.bss)
-        *(COMMON)
-        __bss_end = .;
-    }
+	.text :
+	{
+		*(.text)
+	}
 }

anasos-kernel/src/main.rs

@@ -12,19 +12,21 @@ use anasos_kernel::{
 };
 use x86_64::VirtAddr;
 
-// Symbols defined in `linker.ld`
+// TODO: Symbols defined in `linker.ld`
 
 
 #[no_mangle]
 pub extern "C" fn _start() -> ! {
-    lazy_static! {
-        static ref BOOT_INFO: BootInfo = unsafe { bootinfo::get() };
-    }
+    println!("Hello World{}", "!");
+
+    // lazy_static! {
+    //     static ref BOOT_INFO: BootInfo = unsafe { bootinfo::get() };
+    // }
 
-    println!("boot_info: {:?}", *BOOT_INFO);
+    // println!("boot_info: {:?}", *BOOT_INFO);
 
-    // #[cfg(notest)]
-    kernel_main(&*BOOT_INFO);
+    // // #[cfg(notest)]
+    // kernel_main(&*BOOT_INFO);
 
     // #[cfg(test)]
     // test_kernel_main(&*BOOT_INFO);