feat(kernel): 🎨 update BGRT header

CREDITS.md

@@ -127,6 +127,11 @@ License information can be found in the [LICENSES.md](LICENSES.md) file.
 - [Rust OS Development: UEFI](https://blog.malware.re/2023/09/01/rust-os-part2/index.html)
 - [GUIDs Database](https://github.com/DSecurity/efiSeek/blob/master/data/guids-db.ini)
 
+## BGRT
+- [BGRT on OSDev](https://wiki.osdev.org/BGRT)
+- [BMP File Structure @ Gdansk University of Technology](http://www.ue.eti.pg.gda.pl/fpgalab/zadania.spartan3/zad_vga_struktura_pliku_bmp_en.html)
+- [BGRT @ Purdue University](https://engineering.purdue.edu/ece264/16au/hw/HW13)
+
 ---
 
 Special thanks to all contributors and the creators of the referenced projects and resources!

Kernel/include/acpi.hpp

@@ -86,7 +86,7 @@ namespace ACPI
 			SUBTYPE_SERIAL_RISC_V_SBI_Console = 0x0015,
 
 			SUBTYPE_1394_IEEE1394_HCI = 0x0000,
-			
+
 			SUBTYPE_USB_XHCI = 0x0000,
 			SUBTYPE_USB_EHCI = 0x0001,
 
@@ -193,11 +193,63 @@ namespace ACPI
 		struct BGRTHeader
 		{
 			ACPIHeader Header;
+
+			/**
+			 * Version. This value must be 1.
+			 */
 			uint16_t Version;
-			uint8_t Status;
+
+			/**
+			 * Status of the image
+			 */
+			union
+			{
+				struct
+				{
+					/**
+					 * Indicates that the image graphic is displayed.
+					 */
+					uint8_t Displayed : 1;
+
+					/**
+					 * Orientation
+					 *
+					 * 0b00 - 0˚
+					 * 0b01 - 90˚
+					 * 0b10 - 180˚
+					 * 0b11 - 270˚
+					 */
+					uint8_t OrientationOffset : 2;
+
+					/**
+					 * This field is reserved and must be zero.
+					 */
+					uint8_t Reserved : 5;
+				};
+				uint8_t raw;
+			} Status;
+
+			/**
+			 * Image type
+			 *
+			 * 0 - Bitmap
+			 * 1-255 - Reserved
+			 */
 			uint8_t ImageType;
+
+			/**
+			 * Physical address of the image pointing to firmware's in-memory copy of the image bitmap.
+			 */
 			uint64_t ImageAddress;
+
+			/**
+			 * X-offset of the boot image.
+			 */
 			uint32_t ImageOffsetX;
+
+			/**
+			 * Y-offset of the boot image.
+			 */
 			uint32_t ImageOffsetY;
 		} __packed;