Filter
Top Products
186 Technical Reference
Memory Map
Table 31 lists the system memory map. When BIOS allocates memory space to PCI devices, it
starts just below the APICs and continues downward. Assigning memory space to PCI devices
does not decrease the total available memory in the system because this memory is “reclaimed”
above 4 GB.
The server does not support memory gaps from 512 KB to 640 KB and from 15 MB to 16 MB.
These regions are treated as normal system memory.
Table 31. Memory Map
Address Range Amount Function
00000000 – 0009FFFF 640K Base (conventional) System Memory
000A0000 – 000AFFFF 128K ISA Video buffer
000C0000 – 000D7FFF 96K Add-in Options ROM’s (Video, SCSI…)
000C0000 – 000D7FFF 96K Add-in Options ROM’s
000D8000 – 000DBFFF 16K Allocated to Run time user binary if
enabled/programmed, otherwise can be used for options
ROM’s
000DC000 – 000DFFFF 16K Allocated to Console Redirection if enabled, otherwise
can be used for options ROM’s
000E0000 – 000FFFFF 128K System BIOS Shadowed
00100000 – PCI Memory
allocated to first PCI device
Typically it can go up to 3GB
FEC00000 – FEC0FFFF 64K Reserved. Unused on this platform
Reclaimed. If main memory exceeds this region
FEC10000 – FEC1FFFF 64K IOAPIC allocated to the PID
Reclaimed. If main memory exceeds this region
FEC20000 – FECFFFFF 896K Reserved
Reclaimed. If main memory exceeds this region
FEE00000 – FEF00000 1MB LOCAL APIC
Reclaimed. If main memory exceeds this region
FF000000 – FFDFFFFF 14MB Unused. Reclaimed. If main memory exceeds this
region
FFE00000 – FFFFFFFF 2MB Main System BIOS
100000000 – 1FFFFFFFF 4GB If memory exists