docs: documented basic ACPI implementation

.wiki/Kernel-documentation.md

@@ -326,6 +326,38 @@ More information can be found on the limine project's [GitHub](https://github.co
 
 ## drivers
 
+### acpi/acpi.h
+OSDev Wiki: [ACPI](https://wiki.osdev.org/ACPI)
+
+#### `acpi_init(boot_info)` - function (void)
+Initializes the ACPI (Advanced Configuration and Power Interface).
+
+### acpi/rsdp.h
+OSDev Wiki: [RSDP](https://wiki.osdev.org/RSDP)
+
+#### `rsdp_descriptor_v1_T` - struct [packed]
+The RSDP Table used in ACPI v1.0
+
+| Name         | Type     | Description                                               |
+|--------------|----------|-----------------------------------------------------------|
+| signature    | char[8]  | Needs to be `"RSD PTR "` (with the withespace at the end) |
+| checksum     | uint8_t  | Used to validate the table                                |
+| oem_id       | char[6]  | This string identifies the OEM                            |
+| revision     | uint8_t  | Tells whether the RSDP is version 1 or 2+                 |
+| rsdt_address | uint32_t | The Physical Address of the RSDT                          |
+
+#### `rsdp_descriptor_v2_T` - struct [packed]
+The RSDP Table used in ACPI v2.0 or higher
+
+| Name              | Type                 | Description                                                                      |
+|-------------------|----------------------|----------------------------------------------------------------------------------|
+| descriptor_v1     | rsdp_descriptor_v1_T | A table in the format of the ACPI 1.0 specification                              |
+| length            | uint32_t             | The size of the whole table                                                      |
+| xsdt_address      | uint64_t             | The Address of the XSDT (when available this should be used instead of the RSDT) |
+| checksum_extended | uint8_t              | Used to calculate the checksum of the whole table                                |
+| reserved          | uint8_t[3]           | Can be ignored                                                                   |
+
+
 ### elf/elf.h
 #### `elf_executable_T` - struct
 This struct holds the parsed data of an ELF executable.

kernel/inc/drivers/acpi/rsdp.h

@@ -8,7 +8,7 @@
 typedef struct {
     char                    signature           [8];
     uint8_t                 checksum;
-    char                    oem_id;
+    char                    oem_id              [6];
     uint8_t                 revision;
     uint32_t                rsdt_address;
 } __attribute__((packed)) rsdp_descriptor_v1_T;