1 files changed, 59 insertions, 0 deletions
diff --git a/hw/i386/e820_memory_layout.c b/hw/i386/e820_memory_layout.c
new file mode 100644
index 0000000000..bcf9eaf837
--- /dev/null
+++ b/hw/i386/e820_memory_layout.c
@@ -0,0 +1,59 @@
+/*
+ * QEMU BIOS e820 routines
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/bswap.h"
+#include "e820_memory_layout.h"
+
+static size_t e820_entries;
+struct e820_table e820_reserve;
+struct e820_entry *e820_table;
+
+int e820_add_entry(uint64_t address, uint64_t length, uint32_t type)
+{
+    int index = le32_to_cpu(e820_reserve.count);
+    struct e820_entry *entry;
+
+    if (type != E820_RAM) {
+        /* old FW_CFG_E820_TABLE entry -- reservations only */
+        if (index >= E820_NR_ENTRIES) {
+            return -EBUSY;
+        }
+        entry = &e820_reserve.entry[index++];
+
+        entry->address = cpu_to_le64(address);
+        entry->length = cpu_to_le64(length);
+        entry->type = cpu_to_le32(type);
+
+        e820_reserve.count = cpu_to_le32(index);
+    }
+
+    /* new "etc/e820" file -- include ram too */
+    e820_table = g_renew(struct e820_entry, e820_table, e820_entries + 1);
+    e820_table[e820_entries].address = cpu_to_le64(address);
+    e820_table[e820_entries].length = cpu_to_le64(length);
+    e820_table[e820_entries].type = cpu_to_le32(type);
+    e820_entries++;
+
+    return e820_entries;
+}
+
+int e820_get_num_entries(void)
+{
+    return e820_entries;
+}
+
+bool e820_get_entry(int idx, uint32_t type, uint64_t *address, uint64_t *length)
+{
+    if (idx < e820_entries && e820_table[idx].type == cpu_to_le32(type)) {
+        *address = le64_to_cpu(e820_table[idx].address);
+        *length = le64_to_cpu(e820_table[idx].length);
+        return true;
+    }
+    return false;
+}