diff options
Diffstat (limited to 'sys/ki/ktzopn.x')
| -rw-r--r-- | sys/ki/ktzopn.x | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/sys/ki/ktzopn.x b/sys/ki/ktzopn.x new file mode 100644 index 00000000..8a6c14b9 --- /dev/null +++ b/sys/ki/ktzopn.x @@ -0,0 +1,52 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include <config.h> +include <mach.h> +include "ki.h" + +# KT_ZOPN -- Open a text device. We are called only if the device does not +# reside on the local node. + +procedure kt_zopn (device, osfn, mode, chan) + +int device # device driver code +char osfn[ARB] # packed os filename +int mode # access mode +int chan # receives assigned channel + +pointer bd, bp +int server +int ki_connect(), ki_sendrcv(), ki_getchan(), kmalloc() +include "kichan.com" +include "kii.com" + +begin + server = ki_connect (osfn) + p_arg[2] = mode + + if (ki_sendrcv (server, device, TX_OPN) == ERR) + chan = ERR + else if (p_arg[1] == ERR) + chan = ERR + else if (kmalloc (bd, LEN_TXBDES, TY_STRUCT) == ERR) + chan = ERR + else { + chan = ki_getchan (server, p_arg[1]) + k_bufp[chan] = NULL + + # Init the text buffer and buffer descriptor. Text i/o over the + # KI is buffered, greatly reducing the number of packets sent back + # and forth between nodes and likewise increasing the bandwidth. + # Buffering at the KI layer is necessary because FIO buffers only + # one line of text at a time, leaving blocking and deblocking of + # text lines to the kernel. + + k_bufp[chan] = bd + bp = B_BUFPTR(bd) + B_RP(bd) = bp + B_CI(bd) = 0 + B_ITOP(bd) = bp + B_OTOP(bd) = bp + B_BUFTOP(bd) = bp + SZ_TXBUF + } +end |