GE VMIPMC-5565脉冲输入卡件
控制器启动传输。如果从块到扇区的转换产生分数扇区计数，则返回错误且不传输数据。设备探测功能每当访问指定设备时，都会进行设备探测，并在设备描述符表中输入条目；i、 例如，当系统调用.DSKRD、.DSKWR、.DSKFIG、.DSKFMT和.DSKTRL时，使用调试器命令BH、BO、IOC、IOP、IOT、MAR和MAW。设备探测机制利用SCSI命令“Inquiry”和“Mode Sense”。如果指定的控制器是非SCSI的，则探测只返回“设备存在且未知”的状态。设备探测器使用相关数据在设备描述符表中创建一个条目。输入后，下次进行探测时，只需返回“设备存在”状态（指向设备描述符的指针）。通过162Bug命令进行磁盘I/O以下162Bug指令用于磁盘I/O。有关其使用的详细说明，请参阅Motorola 68K CISC CPU调试包用户手册。向特定磁盘I/O支持发出命令时http://www.mcg.mot.com/literature3-19 3控制器LUN和设备LUN，162Bug会记住这些LUN，以便下一个磁盘命令默认使用相同的控制器和设备。IOI（输入/输出查询）该命令用于探测系统中所有可能的CLUN/DLUN组合，并显示支持该组合的设备的查询数据。设备描述符表只有16个设备描述符的空间；使用IOI命令，您可以查看表并在必要时清除它。IOP（物理磁盘I/O）IOP允许您读取或写入数据块，或以某种方式格式化指定的设备。IOP根据您指定的参数创建一个命令包，然后调用适当的系统调用函数来执行该操作。IOT（I/O教学）IOT允许您更改设备的任何可配置参数和属性。此外，它还允许您查看系统中可用的控制器。IOC（I/O控制）IOC允许您直接发送特定控制器定义的命令包。IOC还可以用于在使用IOP命令后查看生成的设备数据包。BO（引导操作系统）BO将操作系统或控制程序从指定设备读取到内存中，然后将控制转移到该设备。BH（引导和停止）BH将操作系统和控制程序从特定设备读取到存储器中，然后返回控制到162Bug。它用作调试工具。3-20计算机组文献中心网站调试器一般信息3通过162Bug系统调用进行磁盘I/O所有实际访问磁盘的操作都是通过162BugTRAP#15系统调用直接或间接完成的。注意，命令级磁盘操作提供了一种使用这些系统调用的方便方式，而无需编写和执行程序。提供以下系统调用以允许用户程序执行磁盘I/O：有关使用这些和其他系统调用的更多信息，请参阅Motorola 68K CISC CPU用户手册的调试包。为了执行磁盘操作，162Bug最终必须向特定的磁盘控制器模块提供专门为该类型的控制器模块准备的控制器命令包。（这在相应的控制器驱动器模块中完成。）一种类型的控制器模块的命令包通常与不同类型的模块的命令数据包的格式不同。执行磁盘I/O的系统调用设施接受
the controller to initiate the transfer. If the conversion from blocks to sectors yields a fractional sector count, an error is returned and no data is transferred. Device Probe Function A device probe with entry into the device descriptor table is done whenever a specified device is accessed; i.e., when system calls .DSKRD, .DSKWR, .DSKCFIG, .DSKFMT, and .DSKCTRL, and debugger commands BH, BO, IOC, IOP, IOT, MAR, and MAW are used. The device probe mechanism utilizes the SCSI commands “Inquiry” and “Mode Sense.” If the specified controller is non-SCSI, the probe simply returns a status of “device present and unknown”. The device probe makes an entry into the device descriptor table with the pertinent data. After an entry has been made, the next time a probe is done it simply returns with “device present” status (pointer to the device descriptor). Disk I/O via 162Bug Commands These following 162Bug commands are provided for disk I/O. Detailed instructions for their use are found in the Debugging Package for Motorola 68K CISC CPUs User’s Manual. When a command is issued to a particular Disk I/O Support http://www.mcg.mot.com/literature 3-19 3 controller LUN and device LUN, these LUNs are remembered by 162Bug so that the next disk command defaults to use the same controller and device. IOI (Input/Output Inquiry) This command is used to probe the system for all possible CLUN/DLUN combinations and display inquiry data for devices which support it. The device descriptor table only has space for 16 device descriptors; with the IOI command, you can view the table and clear it if necessary. IOP (Physical I/O to Disk) IOP allows you to read or write blocks of data, or to format the specified device in a certain way. IOP creates a command packet from the arguments you have specified, and then invokes the proper system call function to carry out the operation. IOT (I/O Teach) IOT allows you to change any configurable parameters and attributes of the device. In addition, it allows you to see the controllers available in the system. IOC (I/O Control) IOC allows you to send command packets as defined by the particular controller directly. IOC can also be used to look at the resultant device packet after using the IOP command. BO (Bootstrap Operating System) BO reads an operating system or control program from the specified device into memory, and then transfers control to it. BH (Bootstrap and Halt) BH reads an operating system or control program from a specified device into memory, and then returns control to 162Bug. It is used as a debugging tool. 3-20 Computer Group Literature Center Web Site Debugger General Information 3 Disk I/O via 162Bug System Calls All operations that actually access the disk are done directly or indirectly by 162Bug TRAP #15 system calls. Note that the command-level disk operations provide a convenient way of using these system calls without writing and executing a program. The following system calls are provided to allow user programs to do disk I/O: Refer to the Debugging Package for Motorola 68K CISC CPUs User’s Manual for additional information on using these and other system calls. To perform a disk operation, 162Bug must eventually present a particular disk controller module with a controller command packet which has been especially prepared for that type of controller module. (This is accomplished in the respective controller driver module.) A command packet for one type of controller module usually does not have the same format as a command packet for a different type of module. The system call facilities which do disk I/O accept a generalized
