[Qemu-devel] [PATCH] add 40-48 bit RAM range to seabios

[Andrea Arcangeli]

Subject: add 40-48 bit RAM range to seabios

From: Andrea Arcangeli <address@hidden>

Needed to show >1TB RAM to guests.

This uses a new cmos port at 0x5e that shall read zero to be backwards
compatible.

Signed-off-by: Andrea Arcangeli <address@hidden>
---

diff --git a/src/cmos.h b/src/cmos.h
index e4b6462..e810534 100644
--- a/src/cmos.h
+++ b/src/cmos.h
@@ -36,9 +36,10 @@
 #define CMOS_BIOS_BOOTFLAG1      0x38
 #define CMOS_BIOS_DISKTRANSFLAG  0x39
 #define CMOS_BIOS_BOOTFLAG2      0x3d
-#define CMOS_MEM_HIGHMEM_LOW     0x5b
-#define CMOS_MEM_HIGHMEM_MID     0x5c
-#define CMOS_MEM_HIGHMEM_HIGH    0x5d
+#define CMOS_MEM_HIGHMEM_16      0x5b
+#define CMOS_MEM_HIGHMEM_24      0x5c
+#define CMOS_MEM_HIGHMEM_32      0x5d
+#define CMOS_MEM_HIGHMEM_40      0x5e
 #define CMOS_BIOS_SMP_COUNT      0x5f
 
 // CMOS_FLOPPY_DRIVE_TYPE bitdefs
diff --git a/src/post.c b/src/post.c
index 5d0e2cb..3628ff5 100644
--- a/src/post.c
+++ b/src/post.c
@@ -106,9 +106,10 @@ ram_probe(void)
         add_e820(0, rs, E820_RAM);
 
         // Check for memory over 4Gig
-        u64 high = ((inb_cmos(CMOS_MEM_HIGHMEM_LOW) << 16)
-                    | ((u32)inb_cmos(CMOS_MEM_HIGHMEM_MID) << 24)
-                    | ((u64)inb_cmos(CMOS_MEM_HIGHMEM_HIGH) << 32));
+        u64 high = ((inb_cmos(CMOS_MEM_HIGHMEM_16) << 16)
+                    | ((u32)inb_cmos(CMOS_MEM_HIGHMEM_24) << 24)
+                    | ((u64)inb_cmos(CMOS_MEM_HIGHMEM_32) << 32)
+                   | ((u64)inb_cmos(CMOS_MEM_HIGHMEM_40) << 40));
         RamSizeOver4G = high;
         add_e820(0x100000000ull, high, E820_RAM);