vgabios: Fetch _rom_header_size from the global segment when computing the ROM's...

Otherwise, checksum_far is getting called with zero as the length
parameter, and the ROM checksum in the header end up beeing zero
after vga_post() is called.

Signed-off-by: Julian Pidancet <julian.pidancet@gmail.com>

diff --git a/vgasrc/vgabios.c b/vgasrc/vgabios.c
index faf57b16376c4cbad4f804165e78d9b94a1a57eb..d80cd53818d3a6405fce4bfe3aadbc6335e3e54c 100644 (file)
--- a/vgasrc/vgabios.c
+++ b/vgasrc/vgabios.c
@@ -1260,6 +1260,7 @@ vga_post(struct bregs *regs)
     // Fixup checksum
     extern u8 _rom_header_size, _rom_header_checksum;
     SET_VGA(_rom_header_checksum, 0);
-    u8 sum = -checksum_far(get_global_seg(), 0, _rom_header_size * 512);
+    u8 sum = -checksum_far(get_global_seg(), 0,
+                           GET_GLOBAL(_rom_header_size) * 512);
     SET_VGA(_rom_header_checksum, sum);
 }