Find RSD Table in early BIOS memory

Adding functions and structures to read the RSD.

src/kernel/drivers/rsdp/rsdp.cpp

@@ -0,0 +1,46 @@
+#include "rsdp.h"
+
+void printRSD(RSDPTR* rsd){
+    printf("Signature: ");
+    for(int i = 0; i < 8; i++){
+        kterm_put(rsd->signature[i]);
+    }
+    kterm_put('\n');
+
+    printf("OEMID: ");
+    for(int i =0; i < 6 ; i++){
+        kterm_put (rsd->OEMID[i]);
+    }
+    kterm_put('\n');
+
+    printf("Revision: %d\n", rsd->Revision);
+    printf("RSDT Address: 0x%x\n", rsd->RsdtAddress );
+}
+
+RSDPTR* FindRSD(){
+    char* memory_byte = (char*) 0x000f2e14;
+    const void* string = "RSD PTR ";
+
+    for( ; (uint32_t) memory_byte < 0x0100000; memory_byte+=10){
+        if( memcmp(memory_byte , string , 8 ) ==  0 ) {
+        printf("RSD PTR found at 0x%x !\n", memory_byte);
+        break;
+        }
+    }
+
+    printRSD((RSDPTR*) memory_byte);
+    return (RSDPTR*) memory_byte;
+}
+
+
+RSDT* getRSDT(RSDPTR* rsd){
+
+        RSDT* rsdt = (RSDT*) rsd->RsdtAddress;
+
+        printf("OEMID: ");
+        for(int i = 0; i < 6; i++){
+            kterm_put(rsdt->header.OEMID[i]);
+        }
+        kterm_put('\n');
+        return rsdt;
+}

src/kernel/drivers/rsdp/rsdp.h

@@ -0,0 +1,36 @@
+#pragma once
+#include <stdint.h>
+#include "./../../tty/kterm.h"
+#include "../../../libc/include/mem.h"
+struct RSDPTR {
+    char signature[8];
+    uint8_t Checksum ;
+    char OEMID [6];
+    uint8_t Revision;
+    uint32_t RsdtAddress;
+}__attribute__((packed));
+
+struct ACPISDTHeader{
+    char Signature[4];
+    uint32_t Length;
+    uint8_t CheckSum;
+    char OEMID[6];
+    char OEMTableID[8];
+    uint32_t OEMRevision;
+    uint32_t CreatorID;
+    uint32_t CreatorRevision;
+}__attribute__((packed));
+
+
+struct RSDT{
+    struct ACPISDTHeader header;
+    uint32_t PointerToSDT[]; // Length of array : (header.Length - sizeof(header))/ 4
+}__attribute__((packed));
+
+
+//NOTE: only scans EBDA enough to find RSD PTR in QEMU
+RSDPTR* FindRSD();
+
+void printRSD(RSDPTR* rsd);
+
+RSDT* getRSDT(RSDPTR* rsd);