x86_64: initialise memblock using e820

arch/x86_64/e820.c

@@ -0,0 +1,56 @@
+#include "socks/types.h"
+#include <socks/memblock.h>
+#include <socks/printk.h>
+#include <socks/util.h>
+#include <arch/e820.h>
+
+void e820_scan(multiboot_memory_map_t *mmap, size_t len)
+{
+	size_t mem_total = 0, mem_reserved = 0;
+
+	multiboot_memory_map_t *entry = NULL;
+	for (size_t i = 0; i < len; i += sizeof *entry) {
+		entry = (void *)((char *)mmap + i);
+
+		int reserved = 1;
+		const char *type = "unknown";
+		switch (entry->type) {
+		case MULTIBOOT_MEMORY_AVAILABLE:
+			type = "available";
+			reserved = 0;
+			break;
+		case MULTIBOOT_MEMORY_RESERVED:
+			type = "reserved";
+			break;
+		case MULTIBOOT_MEMORY_ACPI_RECLAIMABLE:
+			type = "acpi";
+			break;
+		case MULTIBOOT_MEMORY_NVS:
+			type = "nvs";
+			break;
+		case MULTIBOOT_MEMORY_BADRAM:
+			type = "bad";
+			break;
+		default:
+			break;
+		}
+
+		printk("e820: [mem 0x%016llx-0x%016llx] %s",
+		       entry->addr, entry->addr + entry->len - 1, type);
+
+		memblock_add(entry->addr, entry->len);
+
+		if (reserved) {
+			memblock_reserve(entry->addr, entry->len);
+			mem_reserved += entry->len;
+		}
+		
+		mem_total += entry->len;
+	}
+
+	char str_mem_total[64], str_mem_reserved[64];
+	data_size_to_string(mem_total, str_mem_total, sizeof str_mem_total);
+	data_size_to_string(mem_reserved, str_mem_reserved, sizeof str_mem_reserved);
+
+	printk("e820: total memory: %s, hw reserved: %s", str_mem_total, str_mem_reserved);
+}