using the bootstrap loader

WRITING A CUSTOM FIRST-STAGE DRIVER
5-22
Example
This example illustrates the fundamentals of message passing from the bootable device
controller board to the host CPU board. This example is written in PL/M-86 code and is
intended to be generic in nature.
1************************************************************
* This example illustrates how a host CPU board *
* receives a data message from the bootable *
* controller board located in slot 1 at port lF4H of *
* the MULTIBUS II system. *
* *
* The control portion of the message received is *
* located in the l6-byte array p$status$msg *
* (Peripheral Status Message). The data portion of *
* the message received is located in the l024-byte *
* data array sent$data. *
************************************************************1
SAMPLE_BS$RECEIVE: DO;
DECLARE socket
DECLARE socket$o structure
(host$id
port$id
DECLARE p$status$msg(l6)
DECLARE data$adr
DECLARE data$length
DECLARE flags
DECLARE exception
DECLARE sent$data(1024)
DECLARE slot LITERALLY
DECLARE port LITERALLY
DECLARE length LITERALLY
DECLARE null LITERALLY
CODE: DO;
DWORD;
socket$o.host$id = slot;
socket$o.port$id = port;
data$length = length;
flags = null;
WORD,
WORD) AT (@socket);
BYTE;
DWORD;
WORD;
WORD;
WORD;
BYTE;
'lH' ;
, lF4H' ;
, 400H' ;
'OH' ;
data$adr = CONVERT ADDRESS (@sent$data(O));
Bootstrap Loader