memory: Adding memory size detection

Impact: allow com32 module to detect the amount of memory installed

This commit adds several function:

sanitize_e820_map() to generate a new e820 map that doesn't have
overlaping

memsize_e820() to detect the available memory (in KB)

detect_memsize() to detect the amount of memory by using e820/e801/e88.
It first try to detect the memory via e820. If it fails, it uses e801 as
fallback. If this e801 fails, e88 is used.

1 files changed, 12 insertions, 0 deletions

diff --git a/com32/gplinclude/memory.h b/com32/gplinclude/memory.h
index c9f386d4..9157792f 100644
--- a/com32/gplinclude/memory.h
+++ b/com32/gplinclude/memory.h
@@ -22,6 +22,15 @@
 #define _MEMORY_H_
 #include <stdint.h>
 
+#define E820MAX 128
+#define E820_RAM        1
+#define E820_RESERVED   2
+#define E820_ACPI       3 /* usable as RAM once ACPI tables have been read */
+#define E820_NVS        4
+
+#define RES_START       0xa0000
+#define RES_END         0x100000
+
 struct e820entry {
 	uint64_t addr;	/* start of memory segment */
 	uint64_t size;	/* size of memory segment */
@@ -34,4 +43,7 @@ void get_type(int, char*, int);
 void detect_memory_e820(struct e820entry *desc, int size_map, int *size_found);
 int detect_memory_e801(int*, int*);
 int detect_memory_88(int*);
+unsigned long memsize_e820(struct e820entry *e820, int e820_nr);
+int sanitize_e820_map(struct e820entry *orig_map, struct e820entry *new_bios, short old_nr);
+unsigned long detect_memsize(void);
 #endif