feat: fetch VESA information

boot/loader/loader.asm

@@ -59,7 +59,7 @@ _start:
 	; StupidFS layout
 	; +---------+---------+---------....--+----....---+
 	; | bootsec | stpd sb | i-nodes ...   | data      |
-	; +---------+---------+---------0...--+----....---+
+	; +---------+---------+---------....--+----....---+
 	; 0        512      1024             XXXX        XXXX
 	;
 	
@@ -95,8 +95,7 @@ _start:
 	xor bx, bx
 	call fat_load_binary
 
-	xchg bx, bx
+	; fetch memory map from bios
-    ; fetch memory map from bios
 	call memory_get_map
 	jc .error_memory
 
@@ -187,8 +186,8 @@ common32:
 	jl .2
 .2:
 	
-.3:
 
+.3:
 
 	push STPDBOOT_MAGIC
 

boot/loader/memory.inc

@@ -48,9 +48,15 @@ defn AddressRange
 	;;    ECX   - Buffer Size
 	;;    EBX   - Continuation
 memory_e820_get_map:
+	clc
+@@:
 	mov eax, 0xE820
 	mov ebx, 0x0
-	mov ecx, 'SMAP'
+	mov edx, 'SMAP'
+	jc @f
+	cmp eax, 'SMAP'
+	jne @f
+@@:
 
 	ret
 
@@ -71,10 +77,8 @@ memory_get_for_large_conf:
 	int 0x15
 	jc @f
 	xor ecx, ecx
-	mov cx, ax
+	push ax
-	push ecx
+	push bx
-	mov cx, bx
-	push ecx
 	mov si, szMsgLarge
 	call bios_log
 @@:
@@ -89,6 +93,9 @@ memory_get_for_large_conf:
 	;;    CF - Non-Carry - indicates no error
 	;;    AX - Number of contiguous KB above 1MB
 memory_get_map:
+	call memory_e820_get_map
+	jnc .end
+
 	call memory_get_for_large_conf
 	jnc .end
 	clc
@@ -115,4 +122,4 @@ memory_get_map:
 
 szMsgMaxMemKB db "%x KB above 1MB", 0
 szMsgMaxPage db "%x pages", 0
-szMsgLarge db "%x KB above 1MB - %x * 64 KB above 16MB", 0
+szMsgLarge db "%d KB above 1MB - %d * 64 KB above 16MB", 0

boot/loader/video.inc

@@ -1,11 +1,10 @@
 struc VesaInfo
 {
-	.Signature             dd ?
+	.Signature             dd 'VBE2'
 	.Version               dw ?
 	.OEMNamePtr            dd ?
 	.Capabilities          dd ?
-	.VideoModesOffset      dw ?
+	.VideoModesPtr         dw ?
-	.VideoModesSegment     dw ?
 	.CountOf64KBlocks      dw ?
 	.OEMSoftwareRevision   dw ?
 	.OEMVendorNamePtr      dd ?
@@ -14,7 +13,6 @@ struc VesaInfo
 	.Reserved              db 222 dup(?)
 	.OEMData               db 256 dup(?)
 }
-defn VesaInfo
 
 struc VesaModeInfo
 {
@@ -57,32 +55,59 @@ struc VesaModeInfo
 	.OffScreenMemorySize   dd ?
 	.Reserved2             db 206 dup(?)
 }
-defn VesaModeInfo
 
 video_setup:
+	mov si, szMsgDetectVideo
+	call bios_log
 	clc
-	mov di, [vesa_block_buffer]
+	xchg bx, bx
+	xor ax, ax
+	mov es, ax
+	mov di, vesa_block_buffer
 	mov ax, 0x4F00
 	int 0x10
 	cmp ax, 0x004F
 	jne .err
+	cmp [vesa_block_buffer.Signature], 'VESA'
+	jne .err
+
+	push [vesa_block_buffer.OEMProductNamePtr]
+	push [vesa_block_buffer.OEMVendorNamePtr]
+	push [vesa_block_buffer.CountOf64KBlocks]
+	push [vesa_block_buffer.OEMNamePtr]
+	xor ecx, ecx
+	mov cx, [vesa_block_buffer.Version]
+	push ecx
+	mov si, szMsgVesaInfo
+	call bios_log
 
-	push word [vesa_block_buffer + VesaInfo.VideoModesSegment]
-	pop es
 	mov di, vesa_info_block_buffer
-	mov bx, [vesa_block_buffer + VesaInfo.VideoModesOffset]
+	mov bx, [vesa_block_buffer.VideoModesPtr]
 	mov cx, [bx]
 	cmp cx, 0xFFFF
 	je .err
 
+	clc
 	mov ax, 0x4F01
 	int 0x10
 	cmp ax, 0x004F
 	jne .err
+
+	push dword [vesa_info_block_buffer.Framebuffer]
+	mov si, szMsgFramebuffer
+	call bios_log
 	ret
 .err:
+	mov si, szMsgErrorVesa
+	call bios_log
 	stc
 	ret
 
+align 4
 vesa_block_buffer VesaInfo
 vesa_info_block_buffer VesaModeInfo
+
+szMsgVesaInfo db "Version: %x", CR, LF, "OEM Name: %s", CR, LF, "Total Memory: %d", CR, LF, "Vendor name: %s", CR, LF, "Product name: %s", 0
+szMsgDetectVideo db "Fetch video information.", 0
+szMsgFramebuffer db "Fb: 0x%x", 0
+szMsgErrorVesa db "Failed to detect VBE mode", 0