0x22c unsigned long ramdisk_max
0x230 16 bytes trampoline
0x290 - 0x2cf EDD_MBR_SIG_BUFFER (edd.S)
-0x2d0 - 0x600 E820MAP
-0x600 - 0x7ff EDDBUF (edd.S) for disk signature read sector
-0x600 - 0x7eb EDDBUF (edd.S) for edd data
+0x2d0 - 0xd00 E820MAP
+0xd00 - 0xeff EDDBUF (edd.S) for disk signature read sector
+0xd00 - 0xeeb EDDBUF (edd.S) for edd data