From 0aea2cf7d4c53f49e48c272ac7427ab337b476db Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Fri, 17 Apr 2020 17:47:36 +0200
Subject: Added more precise memory measurement

---
 src/kernel/lib/lib.h    |  4 +++-
 src/kernel/lib/memory.c | 29 +++++++++++++++++++++++++----
 2 files changed, 28 insertions(+), 5 deletions(-)

(limited to 'src/kernel/lib')

diff --git a/src/kernel/lib/lib.h b/src/kernel/lib/lib.h
index 8f4e13f..e107da6 100644
--- a/src/kernel/lib/lib.h
+++ b/src/kernel/lib/lib.h
@@ -32,7 +32,9 @@ void *memset(void *dest, char val, size_t count);
  */
 int memcmp(const void *a_ptr, const void *b_ptr, size_t size);
 
-void memory_init(struct multiboot_tag_basic_meminfo *tag);
+void memory_info_init(struct multiboot_tag_basic_meminfo *tag);
+
+void memory_mmap_init(struct multiboot_tag_mmap *tag);
 
 void memory_print();
 
diff --git a/src/kernel/lib/memory.c b/src/kernel/lib/memory.c
index 2544ee0..db26c47 100644
--- a/src/kernel/lib/memory.c
+++ b/src/kernel/lib/memory.c
@@ -35,11 +35,14 @@ int memcmp(const void *a_ptr, const void *b_ptr, size_t size)
 	return 0;
 }
 
+uint32_t total = 0;
 struct multiboot_tag_basic_meminfo *meminfo = NULL;
 
 uint32_t memory_get_all()
 {
-	if (meminfo != NULL) {
+	if (total != 0) {
+		return total;
+	} else if (meminfo != NULL) {
 		return meminfo->mem_lower + meminfo->mem_upper;
 	} else {
 		warn("Got no memory info, guessing size!");
@@ -54,13 +57,31 @@ uint32_t memory_get_free()
 
 void memory_print()
 {
-	info("Mem lower: 0x%x", meminfo->mem_lower);
-	info("Mem upper: 0x%x", meminfo->mem_upper);
+	if (meminfo != NULL) {
+		info("Mem lower: 0x%x", meminfo->mem_lower);
+		info("Mem upper: 0x%x", meminfo->mem_upper);
+	}
 	info("Total memory found: %dMiB", (memory_get_all() >> 10) + 1);
 	info("Total free memory: %dMiB", (memory_get_free() >> 10) + 1);
 }
 
-void memory_init(struct multiboot_tag_basic_meminfo *tag)
+void memory_info_init(struct multiboot_tag_basic_meminfo *tag)
 {
 	meminfo = tag;
 }
+
+void memory_mmap_init(struct multiboot_tag_mmap *tag)
+{
+	uint32_t sum = 0;
+	struct multiboot_mmap_entry *mmap;
+
+	for (mmap = ((struct multiboot_tag_mmap *)tag)->entries;
+	     (multiboot_uint8_t *)mmap < (multiboot_uint8_t *)tag + tag->size;
+	     mmap = (multiboot_memory_map_t *)((uint32_t)mmap +
+					       ((struct multiboot_tag_mmap *)tag)->entry_size)) {
+		if (mmap->type == MULTIBOOT_MEMORY_AVAILABLE) {
+			sum += mmap->len;
+		}
+	}
+	total = sum >> 10; // I want kb
+}
-- 
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