IS220PPROH1A燃機(jī)卡件,GE使用尺寸
當(dāng)請(qǐng)求磁盤傳輸時(shí)，指定傳輸?shù)拈_始和大小以塊為單位。197Bug將其轉(zhuǎn)換為等效的扇區(qū)規(guī)范，其中然后傳遞給控制器以啟動(dòng)傳輸。如果從塊到扇區(qū)產(chǎn)生分?jǐn)?shù)扇區(qū)計(jì)數(shù)，返回錯(cuò)誤，沒有傳輸數(shù)據(jù)。設(shè)備探針功能每當(dāng)出現(xiàn)以下情況時(shí)，就會(huì)執(zhí)行設(shè)備探測(cè)，并將條目放入設(shè)備描述符表中
訪問指定設(shè)備；i、 當(dāng)系統(tǒng)調(diào)用時(shí)
。
IS220PPROH1A燃機(jī)卡件DSKRD。DSKWR，.DSKCFIG。DSKFMT和。DSKCTRL和調(diào)試器命令BH、BO、，使用IOC、IOP、IOT、MAR和MAW。設(shè)備探測(cè)機(jī)制利用SCSI命令“Inquiry”和“模式感知”。如果指定的控制器不是SCSI，則探測(cè)器將簡(jiǎn)單返回“設(shè)備存在且未知”的狀態(tài)。設(shè)備探測(cè)器進(jìn)入與相關(guān)數(shù)據(jù)一起輸入設(shè)備描述符表。輸入后，下次完成探測(cè)時(shí)，它只返回“設(shè)備存在”狀態(tài)（指向設(shè)備描述符的指針）。通過197Bug命令進(jìn)行磁盤輸入/輸出以下197Bug命令用于磁盤輸入/輸出。詳細(xì)信息MVME197BUG 197Bug調(diào)試中提供了它們的使用說明包裝用戶手冊(cè)。當(dāng)向特定控制器發(fā)出命令時(shí)LUN和設(shè)備LUN，197Bug會(huì)記住這些LUN，以便下一個(gè)disk命令默認(rèn)使用相同的控制器和設(shè)備。IOI（輸入/輸出查詢）IOI允許用戶探測(cè)系統(tǒng)中所有可能的CLUN/DLUN組合并顯示支持它的設(shè)備的查詢數(shù)據(jù)。這個(gè)設(shè)備描述符表只有16個(gè)設(shè)備描述符的空間；用IOI命令，用戶可以查看該表并在必要時(shí)將其清除。IOP（物理磁盤輸入/輸出）IOP允許用戶讀取或?qū)懭霐?shù)據(jù)塊，或格式化指定的設(shè)備以某種方式。IOP根據(jù)參數(shù)創(chuàng)建命令包由用戶指定，然后調(diào)用適當(dāng)?shù)南到y(tǒng)調(diào)用函數(shù)來執(zhí)行退出操作。IOT（輸入/輸出示教）物聯(lián)網(wǎng)允許用戶更改任何可配置的參數(shù)和屬性設(shè)備。此外，它允許用戶查看系統(tǒng)IOC（輸入/輸出控制）IOC允許用戶發(fā)送由特定直接控制。IOC還可用于查看生成的設(shè)備數(shù)據(jù)包使用IOP命令后。BO（引導(dǎo)操作系統(tǒng)）BO從指定設(shè)備讀取操作系統(tǒng)或控制程序然后將控制權(quán)轉(zhuǎn)移到內(nèi)存中。BH（引導(dǎo)和暫停）BH將操作系統(tǒng)或控制程序從指定設(shè)備讀取到內(nèi)存，然后將控制返回到197Bug。它被用作調(diào)試工具。
When a disk transfer is requested, the start and size of the transfer is specified
in blocks. 197Bug translates this into an equivalent sector specification, which
is then passed on to 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 197Bug Commands
These following 197Bug commands are provided for disk I/O. Detailed
instructions for their use are found in the MVME197BUG 197Bug Debugging
Package User’s Manual. When a command is issued to a particular controller
LUN and device LUN, these LUNs are remembered by 197Bug so that the next
disk command defaults to use the same controller and device.
IOI (Input/Output Inquiry)
IOI allows the user 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, the user can view the table and clear it if necessary.
IOP (Physical Input/Output to Disk)
IOP allows the user 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
specified by the user, and then invokes the proper system call function to carry
out the operation.
IOT (Input/Output Teach)
IOT allows the user to change any configurable parameters and attributes of
the device. In addition, it allows the user to see the controllers available in the
system.
IOC (Input/Output Control)
IOC allows the user 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 197Bug. It is used as a debugging tool.
