Added memory.c

Includes routine replacing efilib's LibMemoryMap, and a debug function for
dumping the map to the console. Currently get_memory_map() is only used
for the debug function dump_memory_map.

Thanks to Finnbar Murphy for the blog post that helped me figure out why
my memory map iteration was wrong.
http://blog.fpmurphy.com/2012/08/uefi-memory-v-e820-memory.html

src/arch/x86_64/main.c

@@ -2,6 +2,7 @@
 #include <efilib.h>
 
 #include "console.h"
+#include "memory.h"
 #include "utility.h"
 
 #ifndef GIT_VERSION
@@ -30,6 +31,24 @@ efi_main (EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
 	if (SystemTable->ConOut)
 		Print(L"OutputString: %x\n", SystemTable->ConOut->OutputString);
 
+    dump_memory_map();
+
+	UINTN memmap_size = 0;
+	EFI_MEMORY_DESCRIPTOR *memmap;
+	UINTN memmap_key;
+	UINTN desc_size;
+	UINT32 desc_version;
+
+	memmap = LibMemoryMap(&memmap_size, &memmap_key,
+		&desc_size, &desc_version);
+
+	status = ST->BootServices->ExitBootServices(ImageHandle, memmap_key);
+	CHECK_EFI_STATUS_OR_RETURN(status, "Exiting boot services");
+
+	status = ST->RuntimeServices->SetVirtualAddressMap(
+		memmap_size, desc_size, desc_version, memmap);
+	CHECK_EFI_STATUS_OR_RETURN(status, "Setting memory map");
+
 	while (1) __asm__("hlt");
 	return status;
 }

src/arch/x86_64/memory.c

@@ -0,0 +1,84 @@
+#include <efi.h>
+#include <efilib.h>
+
+#include "memory.h"
+#include "utility.h"
+
+const UINTN PAGE_SIZE = 4096;
+
+const CHAR16 *memory_type_names[] = {
+    L"EfiReservedMemoryType",
+    L"EfiLoaderCode",
+    L"EfiLoaderData",
+    L"EfiBootServicesCode",
+    L"EfiBootServicesData",
+    L"EfiRuntimeServicesCode",
+    L"EfiRuntimeServicesData",
+    L"EfiConventionalMemory",
+    L"EfiUnusableMemory",
+    L"EfiACPIReclaimMemory",
+    L"EfiACPIMemoryNVS",
+    L"EfiMemoryMappedIO",
+    L"EfiMemoryMappedIOPortSpace",
+    L"EfiPalCode",
+    L"EfiPersistentMemory",
+};
+
+const CHAR16 *memory_type_name(UINT32 value) {
+    if (value >= (sizeof(memory_type_names)/sizeof(CHAR16*)))
+        return L"Bad Type Value";
+    return memory_type_names[value];
+}
+
+EFI_STATUS get_memory_map(EFI_MEMORY_DESCRIPTOR **buffer, UINTN *buffer_size,
+                          UINTN *key, UINTN *desc_size, UINT32 *desc_version) {
+    EFI_STATUS status;
+
+    UINTN needs_size = 0;
+    status = BS->GetMemoryMap(&needs_size, 0, key, desc_size, desc_version);
+    if (status != EFI_BUFFER_TOO_SMALL) {
+        CHECK_EFI_STATUS_OR_RETURN(status, "Failed to load memory map");
+    }
+
+    // Give some extra buffer to account for changes.
+    *buffer_size = needs_size + 256;
+    Print(L"Trying to load memory map with size %d.\n", *buffer_size);
+    status = BS->AllocatePool(EfiLoaderData, *buffer_size, (void**)buffer);
+    CHECK_EFI_STATUS_OR_RETURN(status, "Failed to allocate space for memory map");
+
+    status = BS->GetMemoryMap(buffer_size, *buffer, key, desc_size, desc_version);
+    CHECK_EFI_STATUS_OR_RETURN(status, "Failed to load memory map");
+    return EFI_SUCCESS;
+}
+
+EFI_STATUS dump_memory_map() {
+    EFI_MEMORY_DESCRIPTOR *buffer;
+    UINTN buffer_size, desc_size, key;
+    UINT32 desc_version;
+
+    EFI_STATUS status = get_memory_map(&buffer, &buffer_size, &key,
+        &desc_size, &desc_version);
+    CHECK_EFI_STATUS_OR_RETURN(status, "Failed to get memory map");
+
+    const UINTN count = buffer_size / desc_size;
+
+    Print(L"Memory map:\n");
+    Print(L"\t  Descriptor Count: %d (%d bytes)\n", count, buffer_size);
+    Print(L"\t       Version Key: %d\n", key);
+    Print(L"\tDescriptor Version: %d (%d bytes)\n\n", desc_version, desc_size);
+
+    EFI_MEMORY_DESCRIPTOR *end = (EFI_MEMORY_DESCRIPTOR *)((uint8_t *)buffer + buffer_size);
+    EFI_MEMORY_DESCRIPTOR *d = buffer;
+    while (d < end) {
+        UINTN size_bytes = d->NumberOfPages * PAGE_SIZE;
+
+        Print(L"Type: %s  Attr: 0x%x\n", memory_type_name(d->Type), d->Attribute);
+        Print(L"\t Physical  %016llx - %016llx\n", d->PhysicalStart, d->PhysicalStart + size_bytes);
+        Print(L"\t  Virtual  %016llx - %016llx\n\n", d->VirtualStart, d->VirtualStart + size_bytes);
+
+        d = (EFI_MEMORY_DESCRIPTOR *)((uint8_t *)d + desc_size);
+    }
+
+    BS->FreePool(buffer);
+    return EFI_SUCCESS;
+}

src/arch/x86_64/memory.h

@@ -0,0 +1,13 @@
+#pragma once
+#include <efi.h>
+
+const CHAR16 *memory_type_name(UINT32 value);
+
+EFI_STATUS get_memory_map(
+    EFI_MEMORY_DESCRIPTOR **buffer,
+    UINTN *buffer_size,
+    UINTN *key,
+    UINTN *desc_size,
+    UINT32 *desc_version);
+
+EFI_STATUS dump_memory_map();