Hi Tim, Yes, I think the fbcon could be used as a complete console (like nxterm) or just like an output to stdout and stderr, same way I did for using a Segment Display as console:
https://www.youtube.com/watch?v=4za1lhfsct8 Did you read the official documentation about fbcon from Linux? https://docs.kernel.org/fb/fbcon.html It has useful information that could help you, although it is not so deep. There is also a good documentation about tty in general (but it doesn't cover fbcon) https://www.linusakesson.net/programming/tty/index.php BR, Alan On Sat, Mar 8, 2025 at 2:06 PM Tim Hardisty <timhardist...@gmail.com> wrote: > My current thinking is that I am being naive/showing inexperience of > consoles. I suspect that the newline is handled via the console to both > send the command to the host (i.e. NuttX) *and* move to a "physical" > newline on the display. > > So I am looking to monitor keyboard input and look for the '\n', but > yesterday got bogged down in pipes and dup and dup2 lol. > > For the FB LCD to actually behave as a console I think it needs to > handle stdin as well as stdout. If this is right I will probably add a > Kconfig choice to either use this app as a simple stdout device, or a > full blown console...much like nxterm but without the need of the nx > server etc. > > On 08/03/2025 16:50, Alan C. Assis wrote: > > Hi Tim, > > Could you please try to run: "ls -l | hexdump" > > > > It could show if the '\n' is received correctly. > > > > BR, > > > > Alan > > > > On Fri, Mar 7, 2025 at 3:47 PM Tim Hardisty <timhardist...@gmail.com> > wrote: > > > >> I am writing a Framebuffer console app that takes stdout and stderr and > >> renders the text to a framebuffer device. Based on existing NXGL code > >> and example apps. > >> > >> It spawns NSH, and I get the NSH prompt on my LCD - and it basically > >> works. I have also added functions to decode the handful of VT100 codes > >> that the nsh app sends, such as cursor on/off, clear to eol etc. > >> > >> But I am stumped by an apparent lack of a newline being sent to stdout > >> when, for example, you simply hit ENTER on the keyboard; or do a > >> directory listing (ls - l) followed by ENTER. With no newline being sent > >> at the start of the output, the first line of text sits at the end of > >> the current line until there's a '/n' within the stream. > >> > >> I must be missing something, perhaps relating to how the VT100 escape > >> codes should be interpreted or some other console "rule" I haven’t > >> managed to find anywhere. > >> > >> Has anyone got any suggestions - it's driving me crazy!! > >> > >> >
