x86: efi_loader: Build EFI memory map per E820 table

On x86 traditional E820 table is used to pass the memory information
to kernel. With EFI loader we can build the EFI memory map from it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/x86/lib/e820.c

@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <efi_loader.h>
 #include <asm/e820.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -34,3 +35,41 @@ __weak unsigned int install_e820_map(unsigned int max_entries,
 
 	return 4;
 }
+
+#if defined(CONFIG_EFI_LOADER) && !defined(CONFIG_SPL_BUILD)
+void efi_add_known_memory(void)
+{
+	struct e820_entry e820[E820MAX];
+	unsigned int i, num;
+	u64 start, pages;
+	int type;
+
+	num = install_e820_map(ARRAY_SIZE(e820), e820);
+
+	for (i = 0; i < num; ++i) {
+		start = e820[i].addr;
+		pages = ALIGN(e820[i].size, EFI_PAGE_SIZE) >> EFI_PAGE_SHIFT;
+
+		switch (e820[i].type) {
+		case E820_RAM:
+			type = EFI_CONVENTIONAL_MEMORY;
+			break;
+		case E820_RESERVED:
+			type = EFI_RESERVED_MEMORY_TYPE;
+			break;
+		case E820_ACPI:
+			type = EFI_ACPI_RECLAIM_MEMORY;
+			break;
+		case E820_NVS:
+			type = EFI_ACPI_MEMORY_NVS;
+			break;
+		case E820_UNUSABLE:
+		default:
+			type = EFI_UNUSABLE_MEMORY;
+			break;
+		}
+
+		efi_add_memory_map(start, pages, type, false);
+	}
+}
+#endif /* defined(EFI_LOADER) && !defined(CONFIG_SPL_BUILD) */