WIP: ntc-chip: Add new device support
I've ported PostmarketOS to the Next Thing Co (NTC) CHIP.
I'm using the downstream kernel from NTC right now, but this device should support mainline uboot and kernel.
Will experiment with mainline uboot and kernel in the next days.
Important:
TL:DR this device can't be flashed with pmbootstrap right now, I will put manual flashing instructions on the Wiki.
This device uses a raw NAND instead of an eMMC, so it needs its rootfs to be in UBIfs format.
UBIfs (like JFFS2) is different from regular filesystems because it takes care of flash memory management like wear leveling or bad block management.
Right now I haven't found a way to create the UBIfs image from pmbootstrap, so I will write instructions to do so manually in the wiki page.
Once the UBIfs image is created, it can be flashed using fastboot, which requires putting uboot in fastboot mode from the serial console.
Status:
At the moment it is possible to build a pmOS image using the commands explained in the wiki page.
However to boot this image we need to change u-boot configuration, and unfortunately the procedure explained below does not work on all the version of u-boot for CHIP around.
The next step is to package and compile u-boot to provide a uniform bootloader for pmOS.
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Device boots -
USB Ethernet works -
Generate Device Tree blob from source -
Package U-boot for CHIP
Merge request reports
Activity
No, it doesn't support mainline kernel, because mainline kernel lacks MLC NAND support.
By Icenowy Zheng on 2020-03-25T08:01:04
Edited by Ghost User-
If I get it correctly it lacks the drivers of the specific MLC NAND mounted on the CHIP. I might give it a shot and try to write the drivers.
Having mainline kernel, and graphic drivers would mean having modern mobile interfaces like Phosh on the PocketCHIP!
By Federico Amedeo Izzo on 2020-03-25T08:01:04
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I think I got it wrong.
According to this blogpost it's UBIfs that dropped MLC NAND support https://byteporter.com/problem-with-nand/However as of my knowledge, MLC NANDs can also be used in SLC mode (with halved capacity)
Which is what was initially used on the CHIP (4GB space available instead of 8GB)Maybe there is a way of configure the NAND in SLC way and run mainline linux.
By Federico Amedeo Izzo on 2020-03-25T08:21:35
Edited by Administrator
added 1 commit
- 7deaec87 - ntc-chip: Change name from Chip to CHIP
By Federico Amedeo Izzo on 2020-03-25T07:57:59
added category::device + 1 deleted label
added 1 commit
- 4a736759 - ntc-chip: Enable USB Ethernet
By Federico Amedeo Izzo on 2020-03-25T09:01:41
added 1 commit
- a1638ba9 - ntc-chip: Fix deviceinfo checksum
By Federico Amedeo Izzo on 2020-03-25T09:19:17
added 1 commit
- 95b66471 - ntc-chip: Add legacy uboot initramfs option
By Federico Amedeo Izzo on 2020-03-25T12:48:12
added 1 commit
- 70736a10 - ntc-chip: Add post-install script to create symlinks of kernel and initramfs
By Federico Amedeo Izzo on 2020-03-25T13:36:02
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The patch looks mostly fine to me, but there is a device tree blob file. We don't put binary blobs into pmaports. Can you generate it from the kernel sources?
If you don't have the source file, there is also a decompiler for device tree blobs.
Right now I haven't found a way to create the UBIfs image from pmbootstrap, so I will write instructions to do so manually in the wiki page.
It would be easy to add this to pmbootstrap here. (If you want to do so, please move the existing sparse code and the new code for ubifs into new functions, so it does not blow up the existing
install_system_imagefunction too much.)However to boot this image we need to change u-boot configuration, and unfortunately the procedure explained below does not work on all the version of u-boot for CHIP around.
The next step is to package and compile u-boot to provide a uniform bootloader for pmOS.
That's a good way forward. But if necessary, we also have a workaround: generate a dummy initramfs in the linux package that mounts the root filesystem and loads the real initramfs. This is done in linux-samsung-i9100 for example.
This is a very interesting device, thanks for doing the port @symmetrist!
By Oliver Smith on 2020-04-02T16:48:35
Edited by Ghost User -
Thank you for the feedback @ollieparanoid!
I will generate the device tree blob from source.
Integrating UBIfs tools in pmbootstrap seems doable, I will give it a shot in a second time, and will follow your suggestions.
By Federico Amedeo Izzo on 2020-04-02T16:48:35
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I'm sorry but I'm no longer working on this port.
The amount of work turned out to be bigger than I tought and currently I prefer to work on a phone (oneplus-bacon) because it is more rewarding.
I will close this MR but I hope it serves as a reference for anyone who wants to pick this up and finish the port.
By Federico Amedeo Izzo on 2020-04-11T08:52:45