Started working on Physical memory map for memory manager

Makefile

@@ -22,9 +22,9 @@ os: $(BUILD) bootloader kernel $(C_FILES)
 	@echo "Building kern.iso..."
 	@dd if=/dev/zero of=kern.iso bs=512 count=2880 status=none
 	@dd if=$(BUILD)/os.bin of=kern.iso conv=notrunc status=none
-	@dd if=$(BUILD)/testfont.bin of=kern.iso bs=512 seek=35 conv=notrunc status=none
+	@dd if=$(BUILD)/testfont.bin of=kern.iso bs=512 seek=36 conv=notrunc status=none
-	@dd if=$(SRC)/fs/test.txt of=kern.iso bs=512 seek=39 conv=notrunc status=none
+	@dd if=$(SRC)/fs/test.txt of=kern.iso bs=512 seek=40 conv=notrunc status=none
-	@dd if=$(BUILD)/calc.bin of=kern.iso bs=512 seek=40 conv=notrunc status=none
+	@dd if=$(BUILD)/calc.bin of=kern.iso bs=512 seek=41 conv=notrunc status=none
 	@echo "\nDone!\n"
 
 $(BUILD):

notes.txt

@@ -0,0 +1,8 @@
+--- Memory Map ---
+0x1000 - Kernel
+0x5000 - VBE Mode Info Block
+0x6000 - Font
+0x7000 - Filetable (0x7c00 - Bootloader)
+...
+0x10000 - Loaded programs
+

src/filetable.asm

@@ -10,12 +10,12 @@
 ;;
 
 filetable:
-    db "boot",0,0,0,0,0,0, "bin",0,0,4
+    db "boot",0,0,0,0,0,0, "bin",0,0,5
-    db "filetable",0,      "tab",0,4,1
+    db "filetable",0,      "tab",0,5,1
-    db "kernel",0,0,0,0,   "bin",0,5,30
+    db "kernel",0,0,0,0,   "bin",0,6,30
-    db "testfont",0,0,     "fnt",0,35,4
+    db "testfont",0,0,     "fnt",0,36,4
-    db "test",0,0,0,0,0,0, "txt",0,39,1
+    db "test",0,0,0,0,0,0, "txt",0,40,1
-    db "calc",0,0,0,0,0,0, "bin",0,40,2
+    db "calc",0,0,0,0,0,0, "bin",0,41,2
 
 times 512-($-$$) db 0
 

src/kernel.c

@@ -11,8 +11,7 @@
 
 #define PROMPT "#> "
 
-// TODO: Put this at a set address
+char* filetable = (char*)0x7000; // Pretty sure we don't have to care about the bootloader at 0x7c00
-char filetable[512];
 
 // Function declarations
 void printFiletable(char* ft);
@@ -30,14 +29,14 @@ void main() {
 
     // Screen setup
     // TODO: Find font in filetable
-    diskRead(35, 4, (char*)0x6000); // Read font from disk
+    diskRead(36, 4, (char*)0x6000); // Read font from disk
     setupScreen();
     loadFont((char*)0x6000);
 
     clear();
     print("kern.\n\n");
 
-    diskRead(4, 1, filetable); // Read the filetable and store it in memory
+    diskRead(5, 1, filetable); // Read the filetable and store it in memory
 
     // Run Interactive Shell Program
     // TODO: Make it in another file

src/stage1.asm

@@ -4,6 +4,7 @@
 
 %define VIDMEM 0xb800
 %define KERNEL_LOC 0x1000
+%define FILETAB_LOC 0x7000 ; TODO: Read kernel size and location from ft
 %define KERNEL_SIZE 30 ; 15kB
 
 start:
@@ -25,7 +26,7 @@ start:
     mov bx, 0x7e00 ; 2nd stage bootloader location
     
     ; CHS Location
-    mov al, 3   ; Number of sectors to read (2 = 1kB)
+    mov al, 4   ; Number of sectors to read (4 = 2kB)
     mov ch, 0   ; Cylinder
     mov dh, 0   ; Head
     mov cl, 2   ; Sector
@@ -68,7 +69,7 @@ loadKernel:
     mov al, KERNEL_SIZE
     mov ch, 0   ; Cylinder
     mov dh, 0   ; Head
-    mov cl, 6   ; Sector
+    mov cl, 7   ; Sector
     mov dl, [driveNum]
 
     mov ah, 2   ; Read from disk

src/stage2.asm

@@ -7,6 +7,58 @@
 start:
     mov [driveNum], dl
 
+    ; Physical memory map setup
+    xor ax, ax
+    mov es, ax
+
+memMapEntries equ 0x8500
+getMemoryMap:
+    mov di, memMapEntries + 4 ; 4 bytes after memMapEntries
+    xor ebx, ebx
+    xor bp, bp
+    mov edx, "PAMS" ; SMAP in little endian
+    mov eax, 0xe820
+    mov dword [es:di+20], 1 ; Force valid ACPI 3.X entry
+    mov ecx, 24
+    int 0x15
+    jc .error
+
+    cmp eax, "PAMS"
+    jne .error
+    test ebx, ebx
+    jz .error
+
+.nextEntry:
+    mov edx, "PAMS" ; In case BIOS messes with edx
+    mov ecx, 24
+    mov eax, 0xe820
+    int 0x15
+    
+    jcxz .skipEntry
+    mov ecx, [es:di+8] ; Low 32 bits of length
+    or ecx, [es:di+12] ; High 32 bits of length
+    jz .skipEntry
+
+    ; Valid entry
+    inc bp
+    add di, 24 ; Next entry
+
+.skipEntry:
+    test ebx, ebx
+    jz .done
+    jmp .nextEntry
+
+.error:
+    mov si, acpiFuncErr
+    call print
+    cli
+    hlt
+
+.done:
+    mov [memMapEntries], bp
+    clc
+
+vbeSetup:
     ; Setup VBE info
     xor ax, ax
     mov es, ax
@@ -44,7 +96,7 @@ start:
     cmp ax, 0x4f
     jne error
 
-    ; Print values
+    ; Print values (Debug)
     ; mov ax, [modeInfoBlock.xRes]
     ; ror ax, 8
     ; call printHex
@@ -52,7 +104,6 @@ start:
     ; call printHex
     ; mov ax, 0x0e20
     ; int 0x10
-
     ; mov ax, [modeInfoBlock.yRes]
     ; ror ax, 8
     ; call printHex
@@ -60,13 +111,11 @@ start:
     ; call printHex
     ; mov ax, 0x0e20
     ; int 0x10
-
     ; xor ax, ax
     ; mov al, [modeInfoBlock.bpp]
     ; call printHex
     ; mov ax, 0x0e20
     ; int 0x10 
-    
     ; mov al, 0x0a
     ; int 0x10
     ; mov al, 0x0d
@@ -218,6 +267,7 @@ driveNum: db 0
 
 vbeErr: db "VBE Error!", 0
 modeNotFoundErr: db "VBE Mode not found!", 0
+acpiFuncErr: db "ACPI Function not supported!", 0
 
 ;; GDT
 GDT:
@@ -256,7 +306,7 @@ offset: dw 0
 _segment: dw 0 ; segment is a keyword
 mode: dw 0
 
-times 512-($-$$) db 0 ; End Sector 1
+times (512*2)-($-$$) db 0 ; End Sector 2
 
 ;; Sector 2
 vbeInfoBlock:
@@ -331,5 +381,5 @@ modeInfoBlock:
 
     .reserved4: times 190 db 0 
 
-times (512*3)-($-$$) db 0 ; 2 Pad out to 3 sectors
+times (512*4)-($-$$) db 0
 

todo.txt

@@ -3,7 +3,7 @@
 - [x] Multistage Bootloader
 - [ ] Bootloader reads filetable to find files
 - [ ] Makefile refactorin'
-- [ ] Write down where stuff is in memory (0x1000 - kernel, 0x4000? - filetable, 0x5000 - VBE Mode Info, 0x6000 - Font)
+- [x] Write down where stuff is in memory 
 - [ ] "Text" mode (not actually)
     - [ ] Scrolling
     - [ ] Scroll-back