How Linux Boots on an Embedded Device - part 1

[@BreakerSpace]

You will get lower initial bump in viewership metrics on this video, but please don't let that discourage you. Not only people will search for and watch this for a longer time, many would come back to watch again for specific references. KZbin analytics makes creating the popcorn content more rewarding than hearty meals like this, but please don't let that get to you. Thankfully you actually have a product to make (instead of breaking it as a KZbinr as your primary goal) so it gives me hope that you will not break to the pressure of algorithm & I can keep coming back for more great content that KZbin is desperately starting to lack.

[@tomazzaman]

Absolutely, I'm in no rush whatsoever, I prefer to make videos I feel passionate about rather than chasing views. I mean, those are nice, but I'd rather they grow organically because people share the same passion, but for me are not the be all end all. Will continue with content like this, don't worry! :)

[@itsamemarkus]

It's awesome you started this series. From what the previous videos looked like, the router will probably be a really nice device. In addition to that it could be a great learning opportunity when we have those videos (+ maybe good documentation).

[@revealingfacts4all]

just PSA... embedded engineer here. You actually do NOT need a JTAG programmer to walk in the 2nd stage boot loader on many SoCs including NXP. Now, I'm not familiar with your exact SoC but I am with other iMX and S32 SoCs from NXP as well as Jacinto processors from Ti and they all have CPU pins you pull up or down to tell that first stage boot loader, in the CPU, where to look for the 2nd stage boot loader - such as a serial port you connect over USB.

[@tomazzaman]

Thanks for the correction! Much appreciated!

[@omegatotal]

You can also use a raspberry pi as a SPI or other flash ROM programmer in most cases, and it sometimes works in system depending on the system you're working on. I recently backed up the flash on a network switch and then put an open source of variant on it, only a raspberry pi in a few jumper leads were needed

[@pahnazd]

I... understood a few of those words! :D This is way above my knowledge level, but it's still very enjoyable seeing how you progress.

[@tomazzaman]

Thank you!

[@TheMegahafo]

I would seriously consider to buy the device I understand its inner workings. Great series. Thank you.

[@Kabodanki]

This series is incredible, man I will buy one for sure. That is exactly what I wanted, ubiquity won't have my money. Overkill, I don't care lol

[@AhmadSwailem]

I like the way how you share interesting things on the way up .. As usual, Good luck ❤

[@Saphykitten]

You’re doing something you’re passionate about and sharing it with an enthusiasm that is absolutely enchanting. Randomly coming across your video series has encouraged me to upgrade my network and learn more about how networking works. Kudos~

[@tomazzaman]

Thank you!

[@OtoBrglez]

I don’t want to say ur doing god’s work here. But definitely work of many professors of CS around the globe! Beautiful work!

[@m-aslan]

a full tutorial will be great

[@Ginita12]

I watched all the videos , even though I'm not a programmer at all . I'm just curious how your enterprise is evolving little by little. I'm here since you "hacked your isp" video . very interesting channel you have here . keep going .

[@j2klegend]

Thanks for explaining every bit in detail 👍

[@pianoman4Jesus]

Excellent tutorial series, Tomaž! 😎👍

[@ghangj]

I love this.

[@phillipmcmahon5949]

Awesome content once again! I hope your project continues going from strength to strength. Did you make contact with the team over at Vyos?

[@uis246]

Speaking of raw flash chips. You don't need special controller that does wear leveling. Linux has UBIFS - special file system for raw flash devices without FTL.

[@shapelessed]

20:48 - Ahh. The pesky CRC checksum mismatches... I recently added CRC error detection to the filesystem I've been working on, I can say confidently - It was a pain.

[@trentbillington1093]

Haha, chatgpt is probably the most computationally expensive way to convert hex to decimal 😭

[@tomazzaman]

Yep, very likely!

[@CrazyMineCuber]

@@tomazzaman And also the most probable way to get an incorrct answer as well. Unless maybe you are a beginner and try to do it in your head :)

[@Pea-pod]

Hi Tomasz, so given we get no LEDs except a power led which flashes during boot. Any chance you can allow for an oled screen via a knockout panel on the case that can be connected to the i2c bus?

[@interruptlabs]

Nice!

[@tfiatd]

And a reminder to all, this is still peanuts compared to the shit you’ll have to deal with should you choose to do all of this manually.

[@Monkeyindatrees]

Why not using a risc-v chip? Arm will be expensive in licensing. If you want uptimized router then you could also use a fpga

[@tfiatd]

Doubt risc-v hardware is mature enough to both conveniently be there in router form, and to have this level of industry support at the moment. Nothing like mostly preconfigured boot images.

[@tomazzaman]

Exaxctly. Risc-v is not anywhere near prodution ready yet.

[@Monkeyindatrees]

@@tfiatd then find a riscv chip and make the kernel drivers yourself? + freebsd has a much better and solid networking stack. Yes it is the hard route, but. No pain no gain

[@paterley9155]

At 10 minutes when talking about erasing the nor flash, you say 7 zeroes, but only typed 6

[@tomazzaman]

I did put the correct word on the screen with an asterisk.

[@paterley9155]

@@tomazzaman Ahh, must have missed that. Glad you noticed too!

[@dkaaakd]

Isn't ls1046a supported by openocd (even with a config for ardb)? Hence the claim that working with JTAG requires software with a large license cost is false?

[@tomazzaman]

You're not wrong, there are other ways, but debuggers in general are expensive, wouldn't you agree? We also need their IDE for other things (RAM testing), not just JTAG work, so I should have been more clear on that. Thanks!

[@dkaaakd]

@@tomazzaman I would say that debuggers are used to be expensive in general; but then ARM opensourced CMSIS and things started to change. If I understand correctly, you're using LS1046ARDB devboard, which has CMSIS-DAP port (J33). OpenOCD supports CMSIS-DAP, thus I would expect it to be possible to do the flashing using just devboard, micro-usb cable, memory layout and open-source software. Not sure what their IDE does for "RAM testing" (DDR timings validation?), but I expect loading firmware / debugging be just a question of what toolchain you're more familiar with, and if you'd like to invest some time into configuring OSS toolchain.

[@tomazzaman]

Thanks for the heads up! And yes, DDR timings validation is what I had in mind. Also, good stuff you're giving me here. I haven't tried this J33 yet, so maybe that's worth a video in itself? Will report :)

[@tfiatd]

Also no, save yourself the hassle, anything but GPT! That thing has zero clue on this with all the confidence!

[@lanefu]

Always bragging you have an ARM SoC that has vendor support and documentation

[@laser-sj]

And this is exactly why i hate Linux.... its way overcomplicated for what it needs to be. 😂

[@Debloper]

...as opposed to Windows or macOS, that are super simple, very easy, user friendly & completely open source - to compile a custom image to boot into any target ASIC or FPGA. 👁👄👁

[@hexlocation]

Computers are complicated :p

[@int32_]

good luck doing this with windows...

[@sasjadevries]

But his video was all about UBoot and embedded memory... he ran over what happens before Linux boots up.

[@laser-sj]

​@@Debloper as opposed to a ground up built embeded system using open source software.