[fencepost]

I'm pretty sure a lot of stock firmware is based on OpenWRT or used to be, though I'm pretty sure most of them lag well behind the current version. I haven't paid much attention for a while, but I think a lot were based on Kamikaze which is more than 10 years old now.

For the vendors with access to closed-source drivers and chipset info they can likely support devices not supported on the open source packages.

Edit: Per Wikipedia, "Qualcomm's QCA Software Development Kit (QSDK) which is being used as a development basis by many OEMs is an OpenWrt derivative"

It also notes Ubiquiti's wireless router firmware as being derived from OpenWRT, but I thought I remembered discussion of Ubiquiti being derived from a different open source distribution - unless perhaps the routers and wireless devices don't share a code base.

[josteink]

That's pretty cool. I didn't know that.

Looking into the equivalent firmware[1] for my Archer C7 v2, I didn't find any OpenWRT bits though. I was honestly a little bit disappointed.

I guess the difference between hardware revisions might be more fundamental than I assumed.

    DECIMAL       HEXADECIMAL     DESCRIPTION
    --------------------------------------------------------------------------------------------------------
    0             0x0             TP-Link firmware header, firmware version: 1.-15188.3, image version: "",
                                  product ID: 0x0, product version: -956301310, kernel load address: 0x0,
                                  kernel entry point: 0x80002000, kernel offset: 16384512, kernel length:
                                  512, rootfs offset: 855873, rootfs length: 1048576, bootloader offset:
                                  15204352, bootloader length: 0
    71520         0x11760         Certificate in DER format (x509 v3), header length: 4, sequence length: 64
    98560         0x18100         U-Boot version string, "U-Boot 1.1.4 (Mar  5 2018 - 13:57:29)"
    98736         0x181B0         CRC32 polynomial table, big endian
    131584        0x20200         TP-Link firmware header, firmware version: 0.0.3, image version: "",
                                  product ID: 0x0, product version: -956301310, kernel load address: 0x0,
                                  kernel entry point: 0x80002000, kernel offset: 16252928, kernel length:
                                  512, rootfs offset: 855873, rootfs length: 1048576, bootloader offset:
                                  15204352, bootloader length: 0
    132096        0x20400         LZMA compressed data, properties: 0x5D, dictionary size: 33554432 bytes,
                                  uncompressed size: 2451644 bytes
    1180160       0x120200        Squashfs filesystem, little endian, version 4.0, compression:lzma, size:
                                  9878520 bytes, 789 inodes, blocksize: 131072 bytes, created: 2018-03-05
                                  06:16:10

[1] https://static.tp-link.com/2018/201806/20180611/Archer%20C7(...

[mjevans]

The BOM can vary quite a lot between 'revisions', using your product as an example...

https://openwrt.org/toh/tp-link/archer-c7-1750 (Scroll down to the Info Links table and the Wikidevi Info column)

v1 to v2 upgrades the Flash (8MB to 16MB) and uses a slightly different AN+AC wifi chip. v2 and v3 seem pretty similar at a glance. v4 is rated at 12v 2a rather than 2.5a; using a completely different BGN(2.6ghz) chip and also different ethernet chip/switch. v5 is lower power still at 1.5a, but it's less obvious where that change happened due to lack of pictures. A guess based on the simpler antenna list is that it uses less antenna.

[yellowapple]

EnGenius access points also ship with (an outdated and modified version of) OpenWRT.

[bradknowles]

Ubiquiti is based on Vyatta.

[alias_neo]

Which is the predecessor to VyOS: https://www.vyos.io/

It's Open source too for anyone that wants to run it.