From 76de467bdcf33168424db92bb9eca782fe23a770 Mon Sep 17 00:00:00 2001
From: xwashere <xwashere0@protonmail.com>
Date: Tue, 9 Apr 2024 14:01:02 -0400
Subject: [PATCH] [lcrash] ADD: Finish off AcpiInitialize

---
 lcrash/acpi/acpi.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
 lcrash/efi/efi.c   | 45 +++++++++++++++++++++++++++++++++++++++
 lcrash/efi/efi.h   | 18 ++++++++++++++++
 lcrash/lnxboot.c   |  4 ++++
 lcrash/main.c      | 22 +++++++++++++++++++
 5 files changed, 142 insertions(+)
 create mode 100644 lcrash/acpi/acpi.c
 create mode 100644 lcrash/efi/efi.c
 create mode 100644 lcrash/efi/efi.h
 create mode 100644 lcrash/lnxboot.c
 create mode 100644 lcrash/main.c

diff --git a/lcrash/acpi/acpi.c b/lcrash/acpi/acpi.c
new file mode 100644
index 0000000..82e4a1f
--- /dev/null
+++ b/lcrash/acpi/acpi.c
@@ -0,0 +1,53 @@
+#include "acpi.h"
+
+#include "../types.h"
+#include "../lnxboot.h"
+#include "../util.h"
+
+#include "../efi/memmap.h"
+#include "../efi/guid.h"
+#include "../efi/efi.h"
+
+bool AcpiIsPresent = false;
+
+struct AcpiRSDP* AcpiTheRSDP = 0;
+
+void AcpiInitialize() {
+	// Check boot params
+	if (BootBootParams->acpi_rsdp_addr) {
+		AcpiTheRSDP = BootBootParams->acpi_rsdp_addr;
+		goto found;
+	}
+
+	// Check firmware
+	if (EfiPresent()) {
+		const struct EfiSystemTable* SystemTable = EfiGetSystemTable();
+		const struct EfiConfigurationTable* ConfigurationTable = EfiTranslatePointer(SystemTable->ConfigurationTable);
+		for (int i = 0; i < SystemTable->NumberOfTableEntries; i++) { // this used to break because the cckernel decided to give me one last fuck you
+									      // and corrupt random portions of code, i really really hate DEFLATE.
+			if (CompareMemory(&ConfigurationTable[i].VendorGuid, &EFI_ACPI_20_TABLE_GUID, sizeof(EfiGuid))) {
+				AcpiTheRSDP = ConfigurationTable[i].VendorTable;
+				goto found;
+			}
+		}
+	}
+
+	goto fail;
+
+found:	// Is this a valid ACPI table?
+	if (!CompareMemory(AcpiTheRSDP->Signature, "RSD PTR ", 8)) goto fail;
+	
+	// Check the sum
+	u8 Sum = 0;
+	for (int i = 0; i < sizeof(struct AcpiRSDP); i++) Sum += ((u8*)AcpiTheRSDP)[i];
+	if (Sum != 0) goto fail;
+	
+	AcpiIsPresent = true;	
+	return;
+
+fail:   AcpiIsPresent = false;
+	return;
+}
+
+bool AcpiPresent() { return AcpiIsPresent; }
+struct AcpiRSDP* AcpiGetRSDP() { return AcpiTheRSDP; }
diff --git a/lcrash/efi/efi.c b/lcrash/efi/efi.c
new file mode 100644
index 0000000..d4257eb
--- /dev/null
+++ b/lcrash/efi/efi.c
@@ -0,0 +1,45 @@
+#include "efi.h"
+
+#include "../types.h"
+#include "../lnxboot.h"
+
+#include "./memmap.h"
+
+static bool IsPresent = false;
+
+// XXX: This was static but something got fucked up when it was.
+//      investigate later
+const struct EfiSystemTable* SystemTable = 0;
+
+void EfiInitialize() {
+	// Get the system table
+	if ((BootBootParams->efi_info.EfiSystemTable | BootBootParams->efi_info.EfiSystemTableHigh) != 0) {
+		SystemTable = (struct EfiSystemTable*)(
+			(uptr)BootBootParams->efi_info.EfiSystemTable |
+			((uptr)BootBootParams->efi_info.EfiSystemTableHigh << 32)
+		);
+	} else goto fail;
+
+	// Load the memory map
+	if ((BootBootParams->efi_info.EfiMemoryMap | BootBootParams->efi_info.EfiMemoryMapHigh) != 0) {
+		if (BootBootParams->efi_info.EfiMemoryDescriptionSize == 0) goto fail;
+		
+		EfiLoadStoredMemoryMap(
+			(struct EfiMemoryDescription*)(
+				(u64)BootBootParams->efi_info.EfiMemoryMap |
+				((u64)BootBootParams->efi_info.EfiMemoryMapHigh << 32)
+			),
+			BootBootParams->efi_info.EfiMemoryMapSize / BootBootParams->efi_info.EfiMemoryDescriptionSize,
+			BootBootParams->efi_info.EfiMemoryDescriptionSize
+		);
+	} else goto fail;
+
+	IsPresent = true;
+	return;
+
+fail:	IsPresent = false;
+	return;
+}
+
+bool EfiPresent() { return IsPresent; }
+const struct EfiSystemTable* EfiGetSystemTable() { return SystemTable; }
diff --git a/lcrash/efi/efi.h b/lcrash/efi/efi.h
new file mode 100644
index 0000000..7f3ee0a
--- /dev/null
+++ b/lcrash/efi/efi.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "../types.h"
+
+/**
+ * Initialize EFI code if EFI is present
+ */
+void EfiInitialize();
+
+/**
+ * Check if EFI is present
+ */
+bool EfiPresent();
+
+/**
+ * Get the EFI system table
+ */
+const struct EfiSystemTable* EfiGetSystemTable();
diff --git a/lcrash/lnxboot.c b/lcrash/lnxboot.c
new file mode 100644
index 0000000..76aead2
--- /dev/null
+++ b/lcrash/lnxboot.c
@@ -0,0 +1,4 @@
+#include "lnxboot.h"
+
+struct setup_info*  BootSetupInfo = 0;
+struct boot_params* BootBootParams = 0;
diff --git a/lcrash/main.c b/lcrash/main.c
new file mode 100644
index 0000000..78d8b16
--- /dev/null
+++ b/lcrash/main.c
@@ -0,0 +1,22 @@
+/// lcrash entry point
+/// super awesome...
+
+#include "types.h"
+#include "lnxboot.h"
+
+#include "efi/efi.h"
+
+[[noreturn]]
+void entry64(struct boot_params* BootParams) {
+	BootBootParams = BootParams;
+	BootSetupInfo  = (void*)BootParams + 0x1f1;
+
+	// Initialize EFI code if we had EFI
+	EfiInitialize();
+
+	// Initialize ACPI code if we have ACPI
+	AcpiInitialize();
+		
+	// Hang :)	
+	while (1) {}
+}