RE: using xterms for connecting to multiple uarts of the virtual machine

[Chan Kim]

Just an update.
Using xterm is also possible.

See
https://stackoverflow.com/questions/39373236/redirect-multiple-uarts-in-qemu
/39376502#comment130819387_39376502  (alexei's answer)

Thanks.
Chan Kim

>-----Original Message-----
>From: Chan Kim <ckim@etri.re.kr>
>Sent: Monday, October 17, 2022 11:45 AM
>To: 'qemu-discuss@nongnu.org' <qemu-discuss@nongnu.org>
>Subject: RE: using xterms for connecting to multiple uarts of the virtual
>machine
>
>Hello all,
>
>I solved the problem.
>The biggest problem was my interrupt number in the virtual machine (SPI
>number) was different from the dtb, so I matched the uart interrupt
numbers.
>And then I found my input to the linux shell in the xterm sometimes gets
>routed to the guest linux shell and sometimes to the host linux shell.
>(It gave me two different prompt shape for my enter key, and for the 'ls'
>command, it sometimes shows my host file system and some times the VM's
>busybox file system) So I figured what I guessed was right(the xterm is
>used both for VM and my host).
>
>Because I didn't know how to prevent my host machine's shell from  working
>with the xterms, I tried using telnet(I don't know where I saw it, I was
>reading qemu document) and tried this option.
>
>-serial telnet:localhost:4321,server -serial telnet:localhost:4322,server -
>nographic
>
>This makes qemu machine wait for telnet connection at start.
>Then in two other terminals, I opened telnet connections.
>telnet localhost 4321
>telnet localhost 4322
>Now I see u-boot output in one terminal and VM's linux shell window in
>another terminal and I can use the VM's linux shell to test the driver!
>Hope this helps someone later.
>Thank you!
>
>Chan Kim
>
>
>>-----Original Message-----
>>From: Chan Kim <ckim@etri.re.kr>
>>Sent: Friday, October 14, 2022 11:59 AM
>>To: 'qemu-discuss@nongnu.org' <qemu-discuss@nongnu.org>
>>Subject: using xterms for connecting to multiple uarts of the virtual
>>machine
>>
>>Hello all,
>>
>>I once asked about this last March but gave it up to solve it to tackle
>>other problems at that time.
>>Our FPGA board has two uart ports and I used u-boot to port linux and
>>it runs ok on real FPGA board including the busybox shell(the uart and
>>linux output come out to different uart ports).
>>I used qemu virtual machine to analyze the programs and solve some
>problems.
>>My virtual machine (modified from arm virt machine, 6.2.0) also has two
>>uart ports.
>>With loading dtb and linux kernel image on DRAM using '-device
>>loader,file=..,addr=..' option, and using u-boot-spl program in the '-
>>kernel' option, I can run u-boot program and it switches to linux until
>>the busybox shell program comes out.
>>The problem is, when I enter something in the emulated busybox shell,
>>it comes out to qemu monitor. I guess this is because of serial port
>>setting in qemu options.
>>(But when I provide linux kernel image in -kernel option and use qemu-
>>generated dtb, the kernel boots ok and shell runs ok too)
>>
>>Until now, I have been using this option (run running from u-boot).
>>"-nographic -chardev stdio,mux=on,id=char0 -chardev
>>stdio,mux=on,id=char1 - serial chardev:char0 -serial chardev:char1"
>>
>>Now I need to solve this one now to be able to do some simple driver
>>tests(using loadable driver module).
>>I found https://stackoverflow.com/questions/39373236/redirect-multiple-
>>uarts-in-qemu (alexei's answer) and I'm trying to use xterm to connect
>>to my two uart ports.
>>I tried xterm -e /bin/sh - 'while true; sleep 100; done' but xterm
>>window doesn't come up.
>>So I executed 'xterm &' command 3 times and I can see there are 3 new
>>device files generated (for example /dev/pts/25, /dev/pts/26 and
>>/dev/pts/27) And I ran qemu from u-boot and used option "-serial
>>/dev/pts/26 -serial /dev/pts/27" (no -chardev options) and could see
>>the u- boot program output in one xterm (I guess /dev/pts/26) and linux
>>output in another xterm (I guess /dev/pts/27).
>>So the qemu serial outputs are connected to separate xterm applications
>>but when I enter something in the linux shell, the input is taken by my
>>ubuntu host's /bin/sh.
>>How can I use xterm just to be used by virtual machine's serial ports?
>>Or in different words, how can I disconnect xterm from my host
>>machine's shell program?
>>
>>Thank you for reading.
>>Chan Kim
>>