Could that be possible to enable PCIe Large-BAR (≥ 512 MB) on LEGACY BIOS LGA1156 system with GTX 1660 SUPER?
I’ve done DSDT modding (added QWordMemory block) directly into DIP8 chip and it seems that the CPU is capable to address in high memory. It should be quite safe because I have flash programmer (CH341B) and two identical DIP8 chips for the BIOS.
This screenshot taken from portable Windows booted from USB stick.
Here’s lspci output for 1st x16 PCIe slot. Currently there’s an NVMe SSD so it marked as x4 lanes. Depending on which slot utilized by GPU it changes showing of [disabled] [64-bit]. This 00:03.0 is for 1st slot. And 00:05.0 is for 2nd slot. Root port’s [disabled] [64-bit] looks pretty similar to output for 2nd generation Intel CPUs (I checked it on another machine, and people has successfully performed enabling LargeBAR on 2nd generation CPUs accordingly to xCuri0’s repository).
$ sudo lspci -vvv -s 00:03.0
00:03.0 PCI bridge: Intel Corporation Core Processor PCI Express Root Port 1 (rev 11) (prog-if 00 [Normal decode])
Subsystem: ASUSTeK Computer Inc. Device 8383
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0, Cache Line Size: 32 bytes
Interrupts: pin B routed to IRQ 16
Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
I/O behind bridge: f000-0fff [disabled] [16-bit]
Memory behind bridge: f5f00000-f5ffffff [size=1M] [32-bit]
Prefetchable memory behind bridge: 00000000fff00000-00000000000fffff [disabled] [64-bit]
Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
BridgeCtl: Parity- SERR+ NoISA- VGA- VGA16- MAbort- >Reset- FastB2B-
PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
Capabilities: [40] Subsystem: ASUSTeK Computer Inc. Device 8383
Capabilities: [60] MSI: Enable- Count=1/2 Maskable+ 64bit-
Address: 00000000 Data: 0000
Masking: 00000000 Pending: 00000000
Capabilities: [90] Express (v2) Root Port (Slot+), IntMsgNum 0
DevCap: MaxPayload 256 bytes, PhantFunc 0
ExtTag+ RBE+ TEE-IO-
DevCtl: CorrErr- NonFatalErr- FatalErr- UnsupReq-
RlxdOrd- ExtTag+ PhantFunc- AuxPwr- NoSnoop-
MaxPayload 128 bytes, MaxReadReq 128 bytes
DevSta: CorrErr- NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
LnkCap: Port #0, Speed 5GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <512ns, L1 <4us
ClockPM- Surprise+ LLActRep+ BwNot+ ASPMOptComp-
LnkCtl: ASPM Disabled; RCB 64 bytes, LnkDisable- CommClk-
ExtSynch- ClockPM- AutWidDis- BWInt+ AutBWInt+ FltModeDis-
LnkSta: Speed 5GT/s, Width x4
TrErr- Train- SlotClk+ DLActive+ BWMgmt- ABWMgmt-
SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise-
Slot #1, PowerLimit 25W; Interlock- NoCompl-
SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
Control: AttnInd Off, PwrInd Off, Power- Interlock-
SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet- Interlock-
Changed: MRL- PresDet- LinkState-
RootCap: CRSVisible+
RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible+
RootSta: PME ReqID 0000, PMEStatus- PMEPending-
DevCap2: Completion Timeout: Range BCD, TimeoutDis+ NROPrPrP- LTR-
10BitTagComp- 10BitTagReq- OBFF Not Supported, ExtFmt- EETLPPrefix-
EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
FRS- LN System CLS Not Supported, TPHComp- ExtTPHComp- ARIFwd+
AtomicOpsCap: Routing- 32bit- 64bit- 128bitCAS-
DevCtl2: Completion Timeout: 260ms to 900ms, TimeoutDis- ARIFwd-
AtomicOpsCtl: ReqEn- EgressBlck-
IDOReq- IDOCompl- LTR- EmergencyPowerReductionReq-
10BitTagReq- OBFF Disabled, EETLPPrefixBlk-
LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance- SpeedDis-
Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
Compliance Preset/De-emphasis: -6dB de-emphasis, 0dB preshoot
LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete- EqualizationPhase1-
EqualizationPhase2- EqualizationPhase3- LinkEqualizationRequest-
Retimer- 2Retimers- CrosslinkRes: unsupported, FltMode-
Capabilities: [e0] Power Management version 3
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [100 v1] Advanced Error Reporting
UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP-
ECRC- UnsupReq- ACSViol- UncorrIntErr- BlockedTLP- AtomicOpBlocked- TLPBlockedErr-
PoisonTLPBlocked- DMWrReqBlocked- IDECheck- MisIDETLP- PCRC_CHECK- TLPXlatBlocked-
UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP-
ECRC- UnsupReq- ACSViol- UncorrIntErr- BlockedTLP- AtomicOpBlocked- TLPBlockedErr-
PoisonTLPBlocked- DMWrReqBlocked- IDECheck- MisIDETLP- PCRC_CHECK- TLPXlatBlocked-
UESvrt: DLP+ SDES+ TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+
ECRC- UnsupReq- ACSViol- UncorrIntErr- BlockedTLP- AtomicOpBlocked- TLPBlockedErr-
PoisonTLPBlocked- DMWrReqBlocked- IDECheck- MisIDETLP- PCRC_CHECK- TLPXlatBlocked-
CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr- CorrIntErr- HeaderOF-
CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+ CorrIntErr- HeaderOF-
AERCap: First Error Pointer: 00, ECRCGenCap- ECRCGenEn- ECRCChkCap- ECRCChkEn-
MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
HeaderLog: 00000000 00000000 00000000 00000000
RootCmd: CERptEn- NFERptEn- FERptEn-
RootSta: CERcvd- MultCERcvd- UERcvd- MultUERcvd-
FirstFatal- NonFatalMsg- FatalMsg- IntMsgNum 0
ErrorSrc: ERR_COR: 0000 ERR_FATAL/NONFATAL: 0000
Capabilities: [150 v1] Access Control Services
ACSCap: SrcValid+ TransBlk+ ReqRedir+ CmpltRedir+ UpstreamFwd+ EgressCtrl- DirectTrans-
ACSCtl: SrcValid- TransBlk- ReqRedir- CmpltRedir- UpstreamFwd- EgressCtrl- DirectTrans-
Capabilities: [160 v0] Vendor Specific Information: ID=0002 Rev=0 Len=00c <?>
Kernel driver in use: pcieport
Kernel modules: shpchp
I suppose that with AMD GPU or NVIDIA 30xx+ GPU the Linux kernel could set appropriate BAR size automatically and put it into high memory, however GTX 16 series is locked by NVIDIA. Usually lock is bypassed by DXE driver but here’s no DXE/UEFI environment.
Some another outputs from Linux could be found there at the bottom of comments:
Of course pci=realloc doesn’t provides any effect, maybe in docs should be something useful:
Edit by Fernando: Thread moved into the “BIOS Modding Problems” Category and title customized