Hello,
after updating RouterOS, I can update the firmware, too.
Well, the wireless drivers are programmed by MikroTik. What about the firmware files? Where do they come from? Does MikroTik use SDK binaries from the vendor, e.g. from https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/?
I’m only guessing but I’d say that routerboot software is even more MT-only than actual RouterOS because it’s even more low-level stuff (i.e. set up mapping between INTA lines on miniPCIe and IRQ line on CPU) than “simple” HW driver. Routerboot indeed might contain firmware for some particular devices (such as wireless chip or LTE card) but I guess that part would probably come from OEMs of those pieces.
If you mean firmware as the bootloader, it’s probably custom Mikrotik code with some OEM parts. And it only initializes the platform, things like memory timings, PCIe timings etc.
Bootloader contains NO firmware for peripherals like LTE modem or WIFI chipset.
Then there is WIFI and LTE chipset firmware. These are present in NPK as files and loaded by kernel driver on boot up. It’s unlikely for Mikrotik to compile these, they probably just send custom parameters and requests to the manufacturer and he supplies the firmware files to Mikrotik.
Mikrotik is all propietary stuff from Mikrotik running on top of Linux kernel, they don’t even use Qualcomm WiFi drivers.