1=============================== 2IBM 3270 Display System support 3=============================== 4 5This file describes the driver that supports local channel attachment 6of IBM 3270 devices. It consists of three sections: 7 8 * Introduction 9 * Installation 10 * Operation 11 12 13Introduction 14============ 15 16This paper describes installing and operating 3270 devices under 17Linux/390. A 3270 device is a block-mode rows-and-columns terminal of 18which I'm sure hundreds of millions were sold by IBM and clonemakers 19twenty and thirty years ago. 20 21You may have 3270s in-house and not know it. If you're using the 22VM-ESA operating system, define a 3270 to your virtual machine by using 23the command "DEF GRAF <hex-address>" This paper presumes you will be 24defining four 3270s with the CP/CMS commands: 25 26 - DEF GRAF 620 27 - DEF GRAF 621 28 - DEF GRAF 622 29 - DEF GRAF 623 30 31Your network connection from VM-ESA allows you to use x3270, tn3270, or 32another 3270 emulator, started from an xterm window on your PC or 33workstation. With the DEF GRAF command, an application such as xterm, 34and this Linux-390 3270 driver, you have another way of talking to your 35Linux box. 36 37This paper covers installation of the driver and operation of a 38dialed-in x3270. 39 40 41Installation 42============ 43 44You install the driver by installing a patch, doing a kernel build, and 45running the configuration script (config3270.sh, in this directory). 46 47WARNING: If you are using 3270 console support, you must rerun the 48configuration script every time you change the console's address (perhaps 49by using the condev= parameter in silo's /boot/parmfile). More precisely, 50you should rerun the configuration script every time your set of 3270s, 51including the console 3270, changes subchannel identifier relative to 52one another. ReIPL as soon as possible after running the configuration 53script and the resulting /tmp/mkdev3270. 54 55If you have chosen to make tub3270 a module, you add a line to a 56configuration file under /etc/modprobe.d/. If you are working on a VM 57virtual machine, you can use DEF GRAF to define virtual 3270 devices. 58 59You may generate both 3270 and 3215 console support, or one or the 60other, or neither. If you generate both, the console type under VM is 61not changed. Use #CP Q TERM to see what the current console type is. 62Use #CP TERM CONMODE 3270 to change it to 3270. If you generate only 633270 console support, then the driver automatically converts your console 64at boot time to a 3270 if it is a 3215. 65 66In brief, these are the steps: 67 68 1. Install the tub3270 patch 69 2. (If a module) add a line to a file in `/etc/modprobe.d/*.conf` 70 3. (If VM) define devices with DEF GRAF 71 4. Reboot 72 5. Configure 73 74To test that everything works, assuming VM and x3270, 75 76 1. Bring up an x3270 window. 77 2. Use the DIAL command in that window. 78 3. You should immediately see a Linux login screen. 79 80Here are the installation steps in detail: 81 82 1. The 3270 driver is a part of the official Linux kernel 83 source. Build a tree with the kernel source and any necessary 84 patches. Then do:: 85 86 make oldconfig 87 (If you wish to disable 3215 console support, edit 88 .config; change CONFIG_TN3215's value to "n"; 89 and rerun "make oldconfig".) 90 make image 91 make modules 92 make modules_install 93 94 2. (Perform this step only if you have configured tub3270 as a 95 module.) Add a line to a file `/etc/modprobe.d/*.conf` to automatically 96 load the driver when it's needed. With this line added, you will see 97 login prompts appear on your 3270s as soon as boot is complete (or 98 with emulated 3270s, as soon as you dial into your vm guest using the 99 command "DIAL <vmguestname>"). Since the line-mode major number is 100 227, the line to add should be:: 101 102 alias char-major-227 tub3270 103 104 3. Define graphic devices to your vm guest machine, if you 105 haven't already. Define them before you reboot (reipl): 106 107 - DEFINE GRAF 620 108 - DEFINE GRAF 621 109 - DEFINE GRAF 622 110 - DEFINE GRAF 623 111 112 4. Reboot. The reboot process scans hardware devices, including 113 3270s, and this enables the tub3270 driver once loaded to respond 114 correctly to the configuration requests of the next step. If 115 you have chosen 3270 console support, your console now behaves 116 as a 3270, not a 3215. 117 118 5. Run the 3270 configuration script config3270. It is 119 distributed in this same directory, Documentation/s390, as 120 config3270.sh. Inspect the output script it produces, 121 /tmp/mkdev3270, and then run that script. This will create the 122 necessary character special device files and make the necessary 123 changes to /etc/inittab. 124 125 Then notify /sbin/init that /etc/inittab has changed, by issuing 126 the telinit command with the q operand:: 127 128 cd Documentation/s390 129 sh config3270.sh 130 sh /tmp/mkdev3270 131 telinit q 132 133 This should be sufficient for your first time. If your 3270 134 configuration has changed and you're reusing config3270, you 135 should follow these steps:: 136 137 Change 3270 configuration 138 Reboot 139 Run config3270 and /tmp/mkdev3270 140 Reboot 141 142Here are the testing steps in detail: 143 144 1. Bring up an x3270 window, or use an actual hardware 3278 or 145 3279, or use the 3270 emulator of your choice. You would be 146 running the emulator on your PC or workstation. You would use 147 the command, for example:: 148 149 x3270 vm-esa-domain-name & 150 151 if you wanted a 3278 Model 4 with 43 rows of 80 columns, the 152 default model number. The driver does not take advantage of 153 extended attributes. 154 155 The screen you should now see contains a VM logo with input 156 lines near the bottom. Use TAB to move to the bottom line, 157 probably labeled "COMMAND ===>". 158 159 2. Use the DIAL command instead of the LOGIN command to connect 160 to one of the virtual 3270s you defined with the DEF GRAF 161 commands:: 162 163 dial my-vm-guest-name 164 165 3. You should immediately see a login prompt from your 166 Linux-390 operating system. If that does not happen, you would 167 see instead the line "DIALED TO my-vm-guest-name 0620". 168 169 To troubleshoot: do these things. 170 171 A. Is the driver loaded? Use the lsmod command (no operands) 172 to find out. Probably it isn't. Try loading it manually, with 173 the command "insmod tub3270". Does that command give error 174 messages? Ha! There's your problem. 175 176 B. Is the /etc/inittab file modified as in installation step 3 177 above? Use the grep command to find out; for instance, issue 178 "grep 3270 /etc/inittab". Nothing found? There's your 179 problem! 180 181 C. Are the device special files created, as in installation 182 step 2 above? Use the ls -l command to find out; for instance, 183 issue "ls -l /dev/3270/tty620". The output should start with the 184 letter "c" meaning character device and should contain "227, 1" 185 just to the left of the device name. No such file? no "c"? 186 Wrong major number? Wrong minor number? There's your 187 problem! 188 189 D. Do you get the message:: 190 191 "HCPDIA047E my-vm-guest-name 0620 does not exist"? 192 193 If so, you must issue the command "DEF GRAF 620" from your VM 194 3215 console and then reboot the system. 195 196 197 198OPERATION. 199========== 200 201The driver defines three areas on the 3270 screen: the log area, the 202input area, and the status area. 203 204The log area takes up all but the bottom two lines of the screen. The 205driver writes terminal output to it, starting at the top line and going 206down. When it fills, the status area changes from "Linux Running" to 207"Linux More...". After a scrolling timeout of (default) 5 sec, the 208screen clears and more output is written, from the top down. 209 210The input area extends from the beginning of the second-to-last screen 211line to the start of the status area. You type commands in this area 212and hit ENTER to execute them. 213 214The status area initializes to "Linux Running" to give you a warm 215fuzzy feeling. When the log area fills up and output awaits, it 216changes to "Linux More...". At this time you can do several things or 217nothing. If you do nothing, the screen will clear in (default) 5 sec 218and more output will appear. You may hit ENTER with nothing typed in 219the input area to toggle between "Linux More..." and "Linux Holding", 220which indicates no scrolling will occur. (If you hit ENTER with "Linux 221Running" and nothing typed, the application receives a newline.) 222 223You may change the scrolling timeout value. For example, the following 224command line:: 225 226 echo scrolltime=60 > /proc/tty/driver/tty3270 227 228changes the scrolling timeout value to 60 sec. Set scrolltime to 0 if 229you wish to prevent scrolling entirely. 230 231Other things you may do when the log area fills up are: hit PA2 to 232clear the log area and write more output to it, or hit CLEAR to clear 233the log area and the input area and write more output to the log area. 234 235Some of the Program Function (PF) and Program Attention (PA) keys are 236preassigned special functions. The ones that are not yield an alarm 237when pressed. 238 239PA1 causes a SIGINT to the currently running application. You may do 240the same thing from the input area, by typing "^C" and hitting ENTER. 241 242PA2 causes the log area to be cleared. If output awaits, it is then 243written to the log area. 244 245PF3 causes an EOF to be received as input by the application. You may 246cause an EOF also by typing "^D" and hitting ENTER. 247 248No PF key is preassigned to cause a job suspension, but you may cause a 249job suspension by typing "^Z" and hitting ENTER. You may wish to 250assign this function to a PF key. To make PF7 cause job suspension, 251execute the command:: 252 253 echo pf7=^z > /proc/tty/driver/tty3270 254 255If the input you type does not end with the two characters "^n", the 256driver appends a newline character and sends it to the tty driver; 257otherwise the driver strips the "^n" and does not append a newline. 258The IBM 3215 driver behaves similarly. 259 260Pf10 causes the most recent command to be retrieved from the tube's 261command stack (default depth 20) and displayed in the input area. You 262may hit PF10 again for the next-most-recent command, and so on. A 263command is entered into the stack only when the input area is not made 264invisible (such as for password entry) and it is not identical to the 265current top entry. PF10 rotates backward through the command stack; 266PF11 rotates forward. You may assign the backward function to any PF 267key (or PA key, for that matter), say, PA3, with the command:: 268 269 echo -e pa3=\\033k > /proc/tty/driver/tty3270 270 271This assigns the string ESC-k to PA3. Similarly, the string ESC-j 272performs the forward function. (Rationale: In bash with vi-mode line 273editing, ESC-k and ESC-j retrieve backward and forward history. 274Suggestions welcome.) 275 276Is a stack size of twenty commands not to your liking? Change it on 277the fly. To change to saving the last 100 commands, execute the 278command:: 279 280 echo recallsize=100 > /proc/tty/driver/tty3270 281 282Have a command you issue frequently? Assign it to a PF or PA key! Use 283the command:: 284 285 echo pf24="mkdir foobar; cd foobar" > /proc/tty/driver/tty3270 286 287to execute the commands mkdir foobar and cd foobar immediately when you 288hit PF24. Want to see the command line first, before you execute it? 289Use the -n option of the echo command:: 290 291 echo -n pf24="mkdir foo; cd foo" > /proc/tty/driver/tty3270 292 293 294 295Happy testing! I welcome any and all comments about this document, the 296driver, etc etc. 297 298Dick Hitt <rbh00@utsglobal.com> 299