Refactor ACPI table caching to use a static array

sdk/xtdk/hltypes.h

@@ -101,6 +101,12 @@
 #define ACPI_MADT_PLACE_ENABLED                     0 /* Processor Local APIC CPU Enabled */
 #define ACPI_MADT_PLAOC_ENABLED                     1 /* Processor Local APIC Online Capable */
 
+/* ACPI address space definitions */
+#define ACPI_ADDRESS_SPACE_MEMORY                   0x00
+
+/* Maximum number of cached ACPI tables */
+#define ACPI_MAX_CACHED_TABLES                      32
+
 /* Default serial port settings */
 #define COMPORT_CLOCK_RATE                          0x1C200
 #define COMPORT_WAIT_TIMEOUT                        204800
@@ -222,7 +228,7 @@ typedef struct _ACPI_SUBTABLE_HEADER
 typedef struct _ACPI_CACHE_LIST
 {
     LIST_ENTRY ListEntry;
-    ACPI_DESCRIPTION_HEADER Header;
+    PACPI_DESCRIPTION_HEADER Table;
 } ACPI_CACHE_LIST, *PACPI_CACHE_LIST;
 
 /* ACPI Root System Description Table Pointer (RSDP) structure */

xtoskrnl/hl/acpi.cc

@@ -26,8 +26,21 @@ HL::Acpi::CacheAcpiTable(IN PACPI_DESCRIPTION_HEADER AcpiTable)
 {
     PACPI_CACHE_LIST AcpiCache;
 
-    /* Create new ACPI table cache entry */
-    AcpiCache = CONTAIN_RECORD(AcpiTable, ACPI_CACHE_LIST, Header);
+    /* Check if there are free slots in static early-boot cache array */
+    if(CacheCount >= ACPI_MAX_CACHED_TABLES)
+    {
+        /* Cache is full, the table is mapped but not cached */
+        return;
+    }
+
+    /* Get the next available static cache entry */
+    AcpiCache = &CacheEntries[CacheCount];
+    CacheCount++;
+
+    /* Store the pointer to the mapped ACPI table */
+    AcpiCache->Table = AcpiTable;
+
+    /* Insert entry into the global ACPI cache list */
     RTL::LinkedList::InsertTailList(&CacheList, &AcpiCache->ListEntry);
 }
 
@@ -539,10 +552,10 @@ HL::Acpi::QueryAcpiCache(IN ULONG Signature,
         AcpiCache = CONTAIN_RECORD(ListEntry, ACPI_CACHE_LIST, ListEntry);
 
         /* Check if ACPI table signature matches */
-        if(AcpiCache->Header.Signature == Signature)
+        if(AcpiCache->Table->Signature == Signature)
         {
             /* ACPI table found in cache, return it */
-            TableHeader = &AcpiCache->Header;
+            TableHeader = AcpiCache->Table;
             break;
         }
 

xtoskrnl/hl/data.cc

@@ -9,6 +9,12 @@
 #include <xtos.hh>
 
 
+/* ACPI tables cache count */
+ULONG HL::Acpi::CacheCount = 0;
+
+/* ACPI tables cache entries */
+ACPI_CACHE_LIST HL::Acpi::CacheEntries[ACPI_MAX_CACHED_TABLES];
+
 /* ACPI tables cache list */
 LIST_ENTRY HL::Acpi::CacheList;
 

xtoskrnl/includes/hl/acpi.hh

@@ -18,6 +18,8 @@ namespace HL
     class Acpi
     {
         private:
+            STATIC ULONG CacheCount;
+            STATIC ACPI_CACHE_LIST CacheEntries[ACPI_MAX_CACHED_TABLES];
             STATIC LIST_ENTRY CacheList;
             STATIC PACPI_RSDP RsdpStructure;
             STATIC ACPI_SYSTEM_INFO SystemInfo;