Help needed with kernel compilation for an Intel network interface

[areksobiczewski]

kernel: 5.15.35-pcpCore-v8
platform: Raspberri Pi CM4 + Official I/O Board.

I'm tryingi to install a new network card from Intel (PCI-E). It has an i350AM2 chipset. The card doesn't work from the get go with PCP.
I downloaded drivers (source) from Intel's website and I was trying to use this guide: https://github.com/piCorePlayer/pCP-Kernels

I'm stuck at point no. 4 - Compile your driver. The compilation process isn't working as expected.
The guide says:
a) Set all the CONFIG_PLATFORM* = n
b) Then set CONFIG_PLATFORM_ARM_RPI = y (or CONFIG_PLATFORM_ARM64_RPI = y) whichever closest matches your system.

But the makefile from Intel doesn't have such variables. I was trying to compile it without modifying anything with following results:
make[1]: Entering directory '/mnt/mmcblk0p2/tce/kernelsrc' CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_main.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_api.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_ethtool.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_hwmon.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_mbx.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_mac.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_manage.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_nvm.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_param.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_phy.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_procfs.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_vmdq.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_82575.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_i210.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/e1000_base.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_debugfs.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/igb_ptp.o CC [M] /mnt/mmcblk0p2/tce/intel-drivers/kcompat.o /mnt/mmcblk0p2/tce/intel-drivers/igb_main.c: In function 'igb_get_os_driver_version': /mnt/mmcblk0p2/tce/intel-drivers/igb_main.c:10296:7: error: implicit declaration of function 'isdigit' [-Werror=implicit-function-declaration] 10296 | if(!isdigit(*c) && *c != '.') | ^~~~~~~ cc1: some warnings being treated as errors make[2]: *** [scripts/Makefile.build:277: /mnt/mmcblk0p2/tce/intel-drivers/igb_main.o] Error 1 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [Makefile:1868: /mnt/mmcblk0p2/tce/intel-drivers] Error 2 make[1]: Leaving directory '/mnt/mmcblk0p2/tce/kernelsrc' make: *** [Makefile:87: default] Error 2

I've attached the makefile downloaded from Intel to this post.
Makefile.txt

Another thing is that the guide then says: Run: pcp_make_module_extension -k -e < extension name >.
And I don't know what is the name of the extension that should be generated during the compiling process! I'm only guessing that for Intel it should something called "igb" or similar. Nothing like that has been built during my compilations with errors.

Also, after some digging I realized that PCP might have drivers for that Intel NIC but not compiled into the kernel.
Looking at /mnt/mmcblk0p2/tce/kernelsrc/drivers/net/ethernet/intel
I see there is an "igb" folder that is supposed to be the driver for my card / chipset. It also has a makefile. Trying to compile it I get:
/mnt/mmcblk0p2/tce/kernelsrc/drivers/net/ethernet/intel
That makefile is much shorter than the one I downloaded from Intel. Bui it also didn't have any variables related to a platform target.

It's the first time I'm compiling a linux kerner. Today I spend 5 hours trying to solve this - I'm hopeless now... I don't entirely understand the process and I'm not familiar with PCP's achitecture. I need help, I'm out of options.
I think there's no other guide in the PCP documenation related to compiling drivers than the one I reffering in this post. It only has some examples for popular Realtek chips.

Digging thru the internet (Tiny Core Linux forum) I've concluded that I may need an additional module: "i2c-KERNEL". Yet, there's no such thing in PCP...
(https://forum.tinycorelinux.net/index.php/topic,23589.0.html) > Another user there was able to install his Intel NIC with some help.
I don't undestand that process, because I'm not familiar with the Tiny Core and the differences between it and the PCP...

PS: The new Intel NIC I can see using "lspci" but it's not available in "ifconfig" or any similar tool. I concluded it's because of no driver in the kernel.
PS2: A manual contained in the drivers from Intel I downloaded claims completely different things are going to happen during compilation than the ones included in the manual from PCP. I think it's not relevant to how PCP works, so it's of no help.

[paul-1]

Hence the reason I don't maintain out of tree drivers. But the intel driver should be in tree. The IGB driver is built, but possibly not included in the default extensions. IF you look at dmesg, you should see some error as to what might be missing.

All Drivers that are built are included in this archive. https://repo.picoreplayer.org/repo/13.x/aarch64/releases/RPi/src/kernel/modules-5.15.35-pcpCore-v8.tar.xz

You may also need firmware which can be found at kernel.org

[areksobiczewski]

I'll be moving on from this problem, but it remains unsolved. Just the scope of the issue is different now.
Leaving my below remarks for those will stumble upon this topic in the future - it might be not possible (without substantial effort) to use Intel NICs in PiCorePlayer. This is my theory.

All the initiall problems with compiling Intel drivers (igb) are gone now. I was able to compile the code. The root of the issue at hand is that Intel's driver code is buggy and won't compile normally on ARM64 (32 bot probably too). Some moneky patching of the source is needed. Here you can read about the issue and follow the steps to patch the code:
geerlingguy/raspberry-pi-pcie-devices#3
Add #include <linux/ctype.h> to igb_main.c
Meanwhile in other distros those changes have been already applied and the driver is working.

Regardless of the above the IGB driver should be included in the kernel already. And probably is, because the NIC works from the get go for instance on Raspberry Pi OS. I doesn't on PCP, and it also doeas not in Tiny Core Linux.
Here is a discussion where an user like me got his NIC with exactly the same chipset (i350-AM2) working under Tiny Core, which took some work on his end to work:
https://forum.tinycorelinux.net/index.php/topic,23589.0.html
There is only one other thread on their forum that has to do with Intel NICs:
https://forum.tinycorelinux.net/index.php/topic,18469.15.html
I'm only mentioning it for reference purpose.

Contrary to how the situation does look like on Tiny Core, Inte's driver compiled uder PCP (successfully) isn't working at all. A further inspection of dmesg and lspci show literally zero information about the NIC having any issues altogether. Even more strange is that the dmesg entries actually indicate that the card has been started correctly (memory allocation). In the prevously mentioned Github issue by Jeff Gerling he shows how such entries look like (it's exactly like that in my case).
In Jeff's case he was able to detect the network interface. In my case, althought the dmesg entries look exactly alike, the card is not visible. PCI inspection tools clearly show that the PCI card itself is recognized, but hasn't been activated by the kernel (access denied to the device).

My best guess is that PCP already had proper drivers for my NIC, but that driver (and any other driver delivered by Intel as source code and then compiled) doesn't work uder PCP due to some reason.

I'm leaving this problem as unsovled due to lack of debugging data from the NIC that could help me identify what is the nature of the problem when the device is not being actived. I also lack skills necessary for deepened debugging of that kind.

Ofcourse when I compiled the driver I was able to successfuly load it to PCP. No issues there. It's just that the driver when loaded doesn't solve anything.
Raspberry Pi sometimes needs a manual option to be configured in config.txt to work with 32-bit PCI cards. I also tried that without success.
I wanted to also indicate that there is another source of the same IGB driver included with PCP in: /mnt/mmcblk0p2/tce/kernelsrc/drivers/net/ethernet/intel. But it can't be compiled at all - its makefile is almost empty and looks very different that the driver coming from INtel's website.
To solve the issues I tried all possible solutions mentioned in reference links in this post. No success.
I think that in this documents I've mentioned all my findings and what I went thru. Maybe someone in the future would be willing to ponder the problem again. In that case please let me know.

I'm leaving to moderators whether to close this github issue or not.