QUANTA QSSC-S99K 2U User Manual page 61

Output
CF Carry Flag
EAX Signature
ES:DI Buffer Pointer
ECX Buffer Size
EBX Continuation
Address Range Descriptor Structure
Offset in Bytes
0
4
8
12
16
The BaseAddrLow and BaseAddrHigh together are the 64-bit base address of this range. The base address is the physical
address of the start of the range being specified.
The LengthLow and LengthHigh together are the 64-bit length of this range. The length is the physical contiguous length in
bytes of a range being specified.
The Type field describes the usage of the described address range as defined in the following table.
Address Ranges in the Type Field
Valu
Mnemonic
e
1 AddressRangeMemory
2 AddressRangeReserved
3 AddressRangeACPI
4 AddressRangeNVS
Othe
Undefined
r
Non-Carry – Indicates No Error
'SMAP' – Signature to verify correct BIOS revision.
Returned Address Range Descriptor pointer. Same value as on input.
Number of bytes returned by the BIOS in the address range descriptor. The
minimum size structure returned by the BIOS is 20 bytes.
Contains the continuation value to get the next address descriptor. The actual
significance of the continuation value is up to the discretion of the BIOS. The
caller must pass the continuation value unchanged as input to the next iteration of
the E820 call in order to get the next Address Range Descriptor. A return value of
zero means that this is the last descriptor.
NOTE: The BIOS can also indicate that the last descriptor has already been
returned during previous iterations by returning a carry. The caller will ignore any
other information returned by the BIOS when the carry flag is set.
Name Description
BaseAddrLow Low 32 Bits of Base Address
BaseAddrHigh High 32 Bits of Base Address
LengthLow Low 32 Bits of Length in Bytes
LengthHigh High 32 Bits of Length in Bytes
Type Address type of this range
Description
This run is available RAM usable by the operating system.
This run of addresses is in use or reserved by the system and must not be
used by the operating system.
ACPI Reclaim Memory. This run is available RAM usable by the operating
system after it reads the ACPI tables.
ACPI NVS Memory. This run of addresses is in use or reserve by the
system and must not be used by the operating system. This range is
required to be saved and restored across an NVS sleep.
Undefined - Reserved for future use. Any range of this type must be treated
by the OS as if the type returned was AddressRangeReserved.
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Chapter 3 — BIOS