From mboxrd@z Thu Jan 1 00:00:00 1970 From: Herbert Poetzl Date: Thu, 1 Apr 2021 20:45:16 +0200 Subject: Serial console via USB (USBTTY) ... In-Reply-To: References: <20210401111949.GO14419@MAIL.13thfloor.at> <20210401161730.GQ14419@MAIL.13thfloor.at> Message-ID: <20210401184516.GS14419@MAIL.13thfloor.at> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, Apr 01, 2021 at 07:36:14PM +0300, Andy Shevchenko wrote: > On Thu, Apr 1, 2021 at 7:17 PM Herbert Poetzl wrote: >> Hello Andy! >> Thanks for the quick feedback! >> On Thu, Apr 01, 2021 at 04:10:57PM +0300, Andy Shevchenko wrote: >>> On Thu, Apr 1, 2021 at 2:19 PM Herbert Poetzl wrote: >>>> I'm trying to get a serial console via USB working on >>>> STM32MP1 but I'm encountering some problems there ... >>>> The u-boot README suggests to add the following config >>>> entries to the board specific .h file: >>>> CONFIG_USB_DEVICE >>>> CONFIG_USB_TTY >>>> CONFIG_USBD_HS (for high speed support) >>>> CONFIG_SYS_CONSOLE_IS_IN_ENV >>>> ... but when doing so, I get a number of linker errors >>>> which suggest that there is something missing: >>>> https://pastebin.com/raw/bbpCu8jy >>>> Marek (via IRC) suggested that this is because the >>>> USB_TTY seems to be based on the old gadget framework >>>> and needs to be updated to the new one. >>> Precisely! >> Are there any examples of such a conversion or is there >> some guide how to convert drivers from the 'old' framework >> to the 'new' one? >>>> It was also suggested that a port of the Linux serial >>>> function driver would be a good alternative to get >>>> CDC/ACM functionality into u-boot and that Andy might >>>> already be working on this ... >>> I abandoned that, but I can send what I have (it still doesn't >>> properly work to me). >> Would definitely be interesting to see, as it seems that >> other function drivers (those are the f_* ones, as far >> as I understood) seem to work just fine. > Here you are: https://github.com/andy-shev/u-boot/tree/topic/f-serial > No guarantees or anything. It's a pile of something. > Tell me when you get it, so I will remove the branch (let's say > I'll do it within 24 hours anyway). Got it, thanks! >>>> So my questions are: >>>> - What is currently the best/easiest approach to >>>> get a serial console via USB working? >>> Create a support for it. >>> You may consider it as there is no support. >> Okay, how do I best start with that? > Try to read the code of existing functions in U-Boot and Linux > kernel? Yeah, is there a specific function driver which was ported from Linux to U-Boot already or would the serial driver be the first one? >>>> - Is the port from Linux in a stage that it can >>>> be tested and/or finalized within a easonable >>>> amount of time? >>> Not from me (I started but encountered so many issues here and >>> there, besides the fact that it's really time consuming). >> I understand ... >>>> - Can I help getting this working? >>> If you do it yourself. I can help with testing on my platform. >> Great! Thanks in advance! Thanks a bunch, Herbert >> Best, >> Herbert >>> -- >>> With Best Regards, >>> Andy Shevchenko > -- > With Best Regards, > Andy Shevchenko