<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style>P {MARGIN-TOP: 0mm; MARGIN-BOTTOM: 0mm}</style>
</head>
<body>
<div style="FONT-FAMILY: Arial; FONT-SIZE: 10pt" id="ezFormProc_div">
<div style="FONT-FAMILY: Arial" id="msgbody">
<div>
<div style="LINE-HEIGHT: 15pt">
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US"><font face="Courier New">Hello, folks,</font></span></font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US"><span lang="EN-US"><font face="Courier New"><span lang="EN-US"></span></font></span></span></font></span> </p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US">It is a comfort to me that I have people to ask questions here and I hope I could be answering to some hard quetions someday.</span></font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US"></span></font></span><span lang="EN-US"><font face="Courier New"><span lang="EN-US">I've beeing trying to attach a USB keyboard to our embedded
system to open a shell on the LCD display using framebuffer console. The USB host controller is from the opencore(USB1.1) and it works for USB memory.</span></font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US">Some of the boot arguments are (I've tried some variants)</span></font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US">"console=tty1 "<br>
"fbcon=map:0000,font:SUN8x16,vc:1-3 "<br>
"root=/dev/ram "</span></font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US"></span></font></span> </p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">The problem is, after the final sys_execve() which executes /sbin/init of the ramdisk, I cannot see any printf results frome the busybox init_main function not to
mention the shell. So I cannot use shell commands like getty. Using uart as the console I can see printf results in the busybox init_main routine. (I use "console=ttyS,mmio,0xff003000,115200n8 " in that case)</font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">Using some prints on separate uart print routine, I can see from the kbd_event function that the key value is going to current vc which is using tty1. The key value
is then handed to put_queue function where the character is somehow copied to tty buffer. Flush_to_ldisc is scheduled for it and it will probably get passed on to the virtual console. By the way, I guess the keyboard data is delivered to current fg_console
(vc 0 which is using tty1).</font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"></font></span> </p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">Added to this, there is a notifier_call_chain and the notifier block is registered by vcs_poll_data_get function which I don't know weather is necessary or not.
So one of my questions is<span style="mso-spacerun: yes"> </span>if vcs is necessary for my case. (I guess not. There is no other notifier blocks registered)
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
<o:p></o:p></font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"> </p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">I gathered that without inittab (I don't use inittab which should be ok for most cases) the assumed default inittab tty2::askfirst:-/bin/sh tty3::askfirst:-/bin/sh
tty4::askfirst:-/bin/sh is being applied by the busybox so there maybe 3 shells on tty2,tty3, and tty4 running somewhere.</font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">But even if there are shells running I don't know how to switch to those ttys.
</font></span><span lang="EN-US"><font face="Courier New">I tried using Ctrl-Alt F2 (or F3, F4) using the USB keyboard to switch to tty2,3,4 to see if any shell comes up on the LCD but couldn't see it.</font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">I tried using inittab with no avail before.</font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"> </p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><font face="Courier New">And I don't know how the printf in busybox is connected to the kernel. I guess busybox talks with stdio(stdout,stdin..) and the file is connected to the kernel anyhow. I've digged
up how vc driver is connected to the console switch functions and to the bit blitting functions and how the printk is handled in the kernel. But</font>
<span lang="EN-US"><font face="Courier New">these console, tty, framebuffer console.. things are very complex to me. and I hope somebody could point me to what should be checked. Any hint will be deeply appreciated.</font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New"><span lang="EN-US"><font face="Courier New"></font></span></font></span> </p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">Best Regards,</font></span></p>
<p style="MARGIN: 0cm 0cm 0pt" class="MsoPlainText"><span lang="EN-US"><font face="Courier New">Chan</font></span></p>
<p style="LINE-HEIGHT: 15pt; MARGIN: 0cm 0cm 0pt" class="MsoNormal"><span style="FONT-FAMILY: 'Arial','sans-serif'; FONT-SIZE: 10pt" lang="EN-US">_______________________________________________<br>
Kernelnewbies mailing list<br>
<a href="mailto:Kernelnewbies@kernelnewbies.org" target="_blank"><font color="#0000ff">Kernelnewbies@kernelnewbies.org</font></a><br>
<a href="http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies" target="_blank">http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies</a></span></p>
</div>
</div>
</div>
</div>
</body>
</html>