From 560f0303beaac1bfa8966de3fe636657825724da Mon Sep 17 00:00:00 2001
From: Konstantin Aladyshev <aladyshev22@gmail.com>
Date: Fri, 2 Jul 2021 20:02:07 +0300
Subject: Add draft for lesson 28

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
---
 Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c | 69 ++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c

(limited to 'Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c')

diff --git a/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c b/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c
new file mode 100644
index 0000000..88c78b6
--- /dev/null
+++ b/Lesson_28/UefiLessonsPkg/AcpiInfo/AcpiInfo.c
@@ -0,0 +1,69 @@
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+
+#include <Library/BaseMemoryLib.h>
+
+EFI_STATUS
+EFIAPI
+UefiMain (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_ACPI_6_3_ROOT_SYSTEM_DESCRIPTION_POINTER* RSDP = NULL;
+
+  for (UINTN i=0; i<SystemTable->NumberOfTableEntries; i++) {
+    if (CompareGuid(&(SystemTable->ConfigurationTable[i].VendorGuid), &gEfiAcpi20TableGuid)) {
+      Print(L"RSDP table is placed at %p\n\n", SystemTable->ConfigurationTable[i].VendorTable);
+      RSDP = SystemTable->ConfigurationTable[i].VendorTable;
+    }
+  }
+
+  if (!RSDP) {
+    Print(L"No ACPI2.0 table was found in the system\n");
+    return EFI_SUCCESS;
+  }
+
+  if (((CHAR8)((RSDP->Signature >>  0) & 0xFF) != 'R') ||
+      ((CHAR8)((RSDP->Signature >>  8) & 0xFF) != 'S') ||
+      ((CHAR8)((RSDP->Signature >> 16) & 0xFF) != 'D') ||
+      ((CHAR8)((RSDP->Signature >> 24) & 0xFF) != ' ') ||
+      ((CHAR8)((RSDP->Signature >> 32) & 0xFF) != 'P') ||
+      ((CHAR8)((RSDP->Signature >> 40) & 0xFF) != 'T') ||
+      ((CHAR8)((RSDP->Signature >> 48) & 0xFF) != 'R') ||
+      ((CHAR8)((RSDP->Signature >> 56) & 0xFF) != ' ')) {
+    Print(L"Error! RSDP signature is not valid!\n");
+    return EFI_SUCCESS;
+  }
+
+  Print(L"System description tables:\n");
+  Print(L"\tRSDT table is placed at address %p\n", RSDP->RsdtAddress);
+  Print(L"\tXSDT table is placed at address %p\n", RSDP->XsdtAddress);
+  Print(L"\n");
+
+  EFI_ACPI_DESCRIPTION_HEADER* XSDT = (EFI_ACPI_DESCRIPTION_HEADER*)RSDP->XsdtAddress;
+  if (((CHAR8)((XSDT->Signature >>  0) & 0xFF) != 'X') ||
+      ((CHAR8)((XSDT->Signature >>  8) & 0xFF) != 'S') ||
+      ((CHAR8)((XSDT->Signature >> 16) & 0xFF) != 'D') ||
+      ((CHAR8)((XSDT->Signature >> 24) & 0xFF) != 'T')) {
+    Print(L"Error! XSDT signature is not valid!\n");
+    return EFI_SUCCESS;
+  }
+
+  Print(L"Main ACPI tables:\n");
+  UINT64 offset = sizeof(EFI_ACPI_DESCRIPTION_HEADER);
+  while (offset < XSDT->Length) {
+    UINT64* table_address = (UINT64*)((UINT8*)XSDT + offset);
+    EFI_ACPI_6_3_COMMON_HEADER* table = (EFI_ACPI_6_3_COMMON_HEADER*)(*table_address);
+    Print(L"\t%c%c%c%c table is placed at address %p with length 0x%x\n", 
+                                             (CHAR8)((table->Signature>> 0)&0xFF),
+                                             (CHAR8)((table->Signature>> 8)&0xFF),
+                                             (CHAR8)((table->Signature>>16)&0xFF),
+                                             (CHAR8)((table->Signature>>24)&0xFF),
+                                             table,
+                                             table->Length);
+    offset += sizeof(UINT64);
+  }
+
+  return EFI_SUCCESS;
+}
-- 
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