Hi Florian.
I was able to flash my Gigabyte HD 5770 1GB (2x DVI 1x DP 1x HDMI) using Netkas vervet but it only shows boot screen on lower DVI using DVI > VGA adaptor, HDMI do not work,
DP (not tested), so i tried using your Efi 5770MOD2.efi.rom with my orig Rom then boot screen shows on DVI with VGA adaptor and tried booting using HDMI it shows the boot screen but once OSX kicks in it turns black and when i use 2 monitors one in DVI > VGA and 1 HDMI it shows boot screen and display on HDMI, i cannot boot on hdmi without another display connected on DVI, strangely i tried to SMC/PRAM reset on my Mac Pro 1,1 then after reboot HDMI is working fine with boot logo and display even without a secondary monitor connected to the DVI > VGA.. so far hdmi is working great
and the only upper DVI port not working, though when using Lion installer or my modified El Cap installer the screen will go blank once OS X installer kicks in.
can i send you the Original ROM for you to take a look?
ioreg
$ ioreg -r -n "PXS1@0"
+-o PXS1@0 <class IOPCIDevice, id 0x1000001a9, registered, matched, active, bu$
| {
| "reg" = <0000080000000000000000000000000000000000100008420000000000000000$
| "device-id" = <b8680000>
| "vendor-id" = <02100000>
| "ATY,RefCLK" = <8c0a0000>
| "ATY,EFIVersionE" = <"113-C0160A-Y!!">
| "PP_DisableMCDownLoadFeature" = 1
| "PP_RefreshRate" = <3c000000>
| "ATY,EFIDispConfig" = <4d00000000000000>
| "PP_R600ActivityHysteresis" = 5
| "subsystem-vendor-id" = <02100000>
| "IOPCIExpressLinkCapabilities" = 67112193
| "AAPL00,Coherency" = <02000000>
| "acpi-path" = "IOACPIPlane:/_SB/PCI0@0/NRP4@40000/PXS1@ffff"
| "ATY,MRT" = <>
| "PP_UserMaxClockForMultiDisplays" = 1
| "VRAM,totalMB" = 1024
| "model" = <"ATI Radeon HD 5770">
| "ATY,EFIDriverType" = <02>
| "ATY,EFIVersion" = <"NO EBAY!!">
| "pcidebug" = "8:0:0"
| "iofb_no_regptr" = Yes
| "CFG_NO_PP" = No
| "compatible" = <"pci1002,2543","pci1002,68b8","pciclass,030000","PXS1">
| "AsicOnLowPower" = <00000000>
| "IOPCIExpressCapabilities" = 18
| "ATY,EFICompileDate" = <"Jul 5 2010">
| "name" = <"ATY,VervetParent">
| "IOName" = "display"
| "pci-aspm-default" = 0
| "ATY,EFIVersionB" = <"113-C01002-101">
| "pci-function-number" = 0
| "AAPL01,blackscreen-preferences" = <00000008>
| "assigned-addresses" = <100008c200000000000000e00000000000000010180008820$
| "ATY,DeviceID" = <b868>
| "saved-config" = <001002ffff900098001002ffff900098023a8007980858002c00380$
| "ATY,remap-size" = 18446744071562067968
| "IOPCIMSIMode" = Yes
| "ATY,Copyright" = <"Copyright AMD Inc. All Rights Reserved. 2005-2010">
| "ATY,EFIOrientation" = <8010>
| "ATY,PlatformInfo" = <010000000000000000000000000000000000000000000000000$
| "class-code" = <00000300>
| "ATY,PageFlipEnable" = <01000000>
| "IOPCIExpressLinkStatus" = 4353
| "IOInterruptControllers" = ("io-apic-0","IOPCIMessagedInterruptController$
| "subsystem-id" = <43250000>
| "PP_VBlankTime" = <9a020000>
| "IOPCIResourced" = Yes
| "ATY,RevID" = 268864385
| "ATY,bin_image" = <55aa7be92502000000000000000000000000000000000000d80100$
| "PP_R600RaisingMediumPercentage" = 25
| "IOChildIndex" = 1
| "ATY,MemVendorID" = <0600>
| "AAPL,backlight-control" = <00000000>
| "PP_ActivitySamplingInterval" = 1000
| "IOPowerManagement" = {"ChildrenPowerState"=2,"CurrentPowerState"=2,"Capa$
| "PP_BootupDisplayState" = <01000000>
| "ATY,memsize" = 1073741824
| "MVAD" = <001002ffff900098001002ffff900098023a8007980858002c0038046504040$
| "AAPL,slot-name" = <"Slot-1">
| "pci-device-number" = 0
| "ATY,MCLK" = 120000
| "IODeviceMemory" = (({"address"=3758096384,"length"=268435456}),({"addres$
| "PP_R600LoweringHighPercentage" = 25
| "acpi-device" = "IOACPIPlatformDevice is not serializable"
| "ATY,SCLK" = 84997
| "AAPL,aux-power-connected" = <01000000>
| "ATY,EFIEnabledMode" = <02>
| "ATY,TileInfo" = <030000000000000000000000000000000600000000000000>
| "ATY,Rom#" = <"113-C0160C-155">
| "AAPL00,blackscreen-preferences" = <00000008>
| "pci-bus-number" = 8
| "ATY,vram_base" = <00000000>
| "IOInterruptSpecifiers" = (<1000000007000000>,<0700000000000100>)
| "PP_R600RaisingLowPercentage" = 10
| "PP_R600LoweringMediumPercentage" = 10
| "ATY,EFIHWInitStatus" = <00000000>
| "revision-id" = <00000000>
| "ATY,VendorID" = <0210>
| "device_type" = <"ATY,VervetParent">
| "PP_HighSamplingInterval" = 200000
| "IOPCIPMCSState" = 0
| "AAPL02,blackscreen-preferences" = <00000008>
| "HDCPLIB_VERSION" = <"1.500">
| "ATY,MemRevisionID" = <0100>
| "IOHibernateState" = <00000000>
| "ATY,Card#" = <"109-C01601-00">
| "IOPMIsPowerManaged" = Yes
| "VRAM,totalsize" = <00000040>
| }
|
+-o AMD5000Controller@1 <class AMD5000Controller, id 0x1000002d6, registered$
+-o ATY,Vervet@0 <class AtiFbStub, id 0x1000002da, registered, matched, acti$
| +-o ATY_Vervet <class AMDFramebuffer, id 0x1000002e4, registered, matched,$
| +-o AppleMCCSControlModule <class AppleMCCSControlModule, id 0x1000002f7$
| | +-o AppleMCCSParameterHandler <class AppleMCCSParameterHandler, id 0x1$
| +-o AppleUpstreamUserClientDriver <class AppleUpstreamUserClientDriver, $
| +-o AMDNDRVService <class AtiAppServices, id 0x100000330, registered, ma$
| +-o IOFramebufferI2CInterface <class IOFramebufferI2CInterface, id 0x100$
| +-o display0 <class IODisplayConnect, id 0x100000333, registered, matche$
| | +-o AppleDisplay <class AppleDisplay, id 0x100000335, registered, matc$
| +-o IOFramebufferUserClient <class IOFramebufferUserClient, id 0x1000003$
| +-o IOFramebufferSharedUserClient <class IOFramebufferSharedUserClient, $
+-o ATY,Vervet@1 <class AtiFbStub, id 0x1000002db, registered, matched, acti$
| +-o ATY_Vervet <class AMDFramebuffer, id 0x1000002ff, registered, matched,$
| +-o AppleMCCSControlModule <class AppleMCCSControlModule, id 0x100000302$
| | +-o AppleMCCSParameterHandler <class AppleMCCSParameterHandler, id 0x1$
| +-o AppleUpstreamUserClientDriver <class AppleUpstreamUserClientDriver, $
| +-o AMDNDRVService <class AtiAppServices, id 0x100000337, registered, ma$
| +-o IOFramebufferI2CInterface <class IOFramebufferI2CInterface, id 0x100$
| +-o IOFramebufferUserClient <class IOFramebufferUserClient, id 0x1000003$
+-o ATY,Vervet@2 <class AtiFbStub, id 0x1000002dc, registered, matched, acti$
| +-o ATY_Vervet <class AMDFramebuffer, id 0x100000305, registered, matched,$
| +-o AppleMCCSControlModule <class AppleMCCSControlModule, id 0x100000308$
| | +-o AppleMCCSParameterHandler <class AppleMCCSParameterHandler, id 0x1$
| +-o AppleUpstreamUserClientDriver <class AppleUpstreamUserClientDriver, $
| +-o AMDNDRVService <class AtiAppServices, id 0x100000339, registered, ma$
| +-o IOFramebufferI2CInterface <class IOFramebufferI2CInterface, id 0x100$
| +-o IOFramebufferUserClient <class IOFramebufferUserClient, id 0x1000003$
+-o AMDSupport <class AMDSupport, id 0x1000002d7, registered, matched, activ$
+-o AMDJuniperGraphicsAccelerator <class AMDJuniperGraphicsAccelerator, id 0$
+-o AMDRadeonX3000_AMDAccel2DContext <class AMDRadeonX3000_AMDAccel2DConte$
+-o AMDRadeonX3000_AMDAccel2DContext <class AMDRadeonX3000_AMDAccel2DConte$
+-o AMDRadeonX3000_AMDAccel2DContext <class AMDRadeonX3000_AMDAccel2DConte$
+-o AMDR8xxSurface <class AMDR8xxSurface, id 0x100000345, !registered, !ma$
+-o AMDR8xxSurface <class AMDR8xxSurface, id 0x100000346, !registered, !ma$
+-o AMDR8xxSurface <class AMDR8xxSurface, id 0x100000347, !registered, !ma$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
+-o AMDRadeonX3000_AMDAccelSharedUserClient <class AMDRadeonX3000_AMDAccel$
+-o AMDR8xxGLContext <class AMDR8xxGLContext, id 0x10000034e, !registered,$
+-o AMDR8xxSurface <class AMDR8xxSurface, id 0x100000353, !registered, !ma$
+-o AMDR8xxSurface <class AMDR8xxSurface, id 0x100000354, !registered, !ma$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
+-o AMDR8xxSurface <class AMDR8xxSurface, id 0x1000003c8, !registered, !ma$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
+-o AMDRadeonX3000_AMDAccelSharedUserClient <class AMDRadeonX3000_AMDAccel$
+-o AMDR8xxGLContext <class AMDR8xxGLContext, id 0x10000044f, !registered,$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
+-o AMDRadeonX3000_AMDAccelSharedUserClient <class AMDRadeonX3000_AMDAccel$
+-o AMDR8xxGLContext <class AMDR8xxGLContext, id 0x100000515, !registered,$
+-o AMDRadeonX3000_AMDAccelDevice <class AMDRadeonX3000_AMDAccelDevice, id$
UPDATE:
I got a hold of DVI > HDMI adapter since my monitor don't have DVI and only have DSUB & HDMI, i think my ROM is near perfect the only issue is when i use any installer the screen will go blank once OSX installer kicks in when using HDMI port.
1. Lower DVI (DVI>VGA = Bootscreen,Desktop, DVI>HDMI = Bootscreen,Desktop)
2. Upper DVI (DVI>VGA = Bootscreen but Low Resolution,Desktop, DVI>HDMI = NO Bootscreen,Desktop)
3. HDMI (Bootscreen, Desktop) - turns black when using any installer when OS X installer kicks in.
4. DisplayPort(DP>HDMI = Bootscreen) - turns black when OS X kicks in.
Mac Pro 1,1
16GB RAM
Gigabyte HD 5770 1GB
El Capitan/ Piker Boot.fi