# PCI Slots Unavailability **URL:** \ **Category:** HiFive Unmatched\ **Created:** [December 22, 2021, 5:25am UTC](https://forums.sifive.com/t/pci-slots-unavailability/5528 "2021-12-22T05:25:11Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![kngmu](https://avatars.discourse-cdn.com/v4/letter/k/9dc877/32.png) [@kngmu](https://forums.sifive.com/u/kngmu)\ **Post date:** [December 22, 2021, 5:25am UTC](https://forums.sifive.com/t/pci-slots-unavailability/5528/1 "2021-12-22T05:25:11Z")
Respected Team, In the Hifive SiFive Unmatched Board, we are running the default linux OS provided by SiFive in the microSD card. It is able to detect the PCI slot number 07 as shown in the below steps which are generated as output in the terminal root@unmatched:~# cd /sys/bus/pci/devices root@unmatched:/sys/bus/pci/devices# ls 0000:00:00.0 0000:02:00.0 0000:02:03.0 0000:02:08.0 0000:07:00.0 0000:01:00.0 0000:02:02.0 0000:02:04.0 0000:04:00.0 Linux OS But when we use the Ubuntu OS for HiFive SiFive Unmatched board given in the below link: > **[Ubuntu 20.04.3 LTS (Focal Fossa)](https://cdimage.ubuntu.com/releases/20.04.3/release/)** > > CD images for Ubuntu 20.04.3 LTS (Focal Fossa) It is unable to detect the PCI slot number 07 as shown in the available PCI device list below obtained from the terminal ubuntu@ubuntu:~$ cd /sys/bus/pci/devices ubuntu@ubuntu:/sys/bus/pci/devices$ ls 0000:00:00.0 0000:02:00.0 0000:02:03.0 0000:02:08.0 0000:01:00.0 0000:02:02.0 0000:02:04.0 0000:04:00.0 Ubuntu OS Kindly suggest how we can resolve this issue. ---
**Author:** ![davidlt](https://avatars.discourse-cdn.com/v4/letter/d/e480ec/32.png) [@davidlt](https://forums.sifive.com/u/davidlt)\ **Post date:** [December 22, 2021, 7:45am UTC](https://forums.sifive.com/t/pci-slots-unavailability/5528/2 "2021-12-22T07:45:30Z")
What is connected to the PCI? FUSDK is not a full proper Linux **desktop** distribution, it’s more of a demo platform based on OE. We don’t have all the possible drivers enabled as you would find on Ubuntu/Fedora/openSUSE/etc. Looking at my systems I see that “07:00.0” and “07:00.1” are AMD GPU that I am using. You can look at `/proc/config.gz` and check if kernel support is enabled for your particular PCI device. ---
**Author:** ![kngmu](https://avatars.discourse-cdn.com/v4/letter/k/9dc877/32.png) [@kngmu](https://forums.sifive.com/u/kngmu)\ **Post date:** [December 29, 2021, 9:23am UTC](https://forums.sifive.com/t/pci-slots-unavailability/5528/3 "2021-12-29T09:23:34Z")
Respected Team, Thank you for the warm reply. We are connecting an FPGA device through PCIe connector on the Hifive Sifive Unmatched Board. We have compared the PCI slots by checking in both Freedom U SDK Linux and Ubuntu images. There is some misunderstanding, we are able to detect the device in FUSDK and not in Ubuntu image. Please can you suggest what to look for in the config file to enable device support? We compared the FUSDK and Ubuntu config files and checked for PCIe related support. Can you please suggest any solution from the comparison? Looking forward to hearing from you Freedom U SDK Config PCI\_EAER\_INJECT=m Config PCI\_REALLOC enable auto is not set Config Hot Plug PCI\_CPCI is not set DW\_PLAT is not set Cadence support is not set Switch-tech=y Config PCCard is not set Config Debug Driver is not set Config RAPIDIO is not set #Hardware Tracing Support #CONFIG\_FPGA is not set #STMicroelectronics STM32 SOC audio support #CONFIG\_SND\_SOC\_XTFPGA\_I2S is not set Ubuntu Config\_PCI\_EAER\_INJECT is not set Config PCI\_REALLOC enable auto=y Config Hot Plug PCI\_CPCI=y DW\_PLAT=y Cadence support is set Switch\_tech=m Config PCCard is not set Config Debug Driver is not set Config RAPIDIO\_TSI57X=m #Hardware Tracing Support CONFIG\_FPGA=m CONFIG\_FPGA\_MGR\_ALTERA\_PS\_SPI=m CONFIG\_FPGA\_MGR\_ALTERA\_CVP=m CONFIG\_FPGA\_MGR\_XILINX\_SPI=m CONFIG\_FPGA\_MGR\_ICE40\_SPI=m CONFIG\_FPGA\_MGR\_MACHXO2\_SPI=m CONFIG\_FPGA\_BRIDGE=m CONFIG\_FPGA\_REGION=m CONFIG\_OF\_FPGA\_REGION=m CONFIG\_FPGA\_DFL=m CONFIG\_FPGA\_DFL\_FME=m CONFIG\_FPGA\_DFL\_FME\_MGR=m CONFIG\_FPGA\_DFL\_FME\_BRIDGE=m CONFIG\_FPGA\_DFL\_FME\_REGION=m CONFIG\_FPGA\_DFL\_AFU=m CONFIG\_FPGA\_DFL\_PCI=m ---
**Author:** ![davidlt](https://avatars.discourse-cdn.com/v4/letter/d/e480ec/32.png) [@davidlt](https://forums.sifive.com/u/davidlt)\ **Post date:** [January 7, 2022, 8:26am UTC](https://forums.sifive.com/t/pci-slots-unavailability/5528/4 "2022-01-07T08:26:16Z")
I don’t have PCIe FPGA to test with. The best suggestion is to do a diff between defconfigs and slowly merge changes into Ubuntu defconfig, recompile the kernel and test.