DT680B-E系統(tǒng)卡件，ABB使用指導(dǎo)
當(dāng)調(diào)試固件等待各種控制器和驅(qū)動器達到速度然后開始實際的輸入/輸出：程序指向指定媒體的卷ID加載到RAM中，并將控制傳遞給它。然而，如果在此期間用戶希望在沒有自動啟動的情況下獲得控制，可以按下<BREAK>鍵或軟件中止或重置開關(guān)。自動引導(dǎo)由ENV命令中包含的參數(shù)控制。這些參數(shù)允許選擇特定的引導(dǎo)設(shè)備和文件，并允許啟動延遲編程。
DT680B-E系統(tǒng)卡件有關(guān)詳細信息，請參閱附錄A中的ENV命令更多詳細信息。雖然流式磁帶可以用于自動引導(dǎo)，但相同電源必須連接到流式磁帶驅(qū)動器、控制器和MVME197LE。通電時磁帶控制器將流式磁帶定位到加載點其中可以正確讀取和使用卷ID。然而，如果MVME197LE失去電源，但控制器而磁帶恰好不在加載點
所需命令序列（附加和回放）無法賦予控制器，并且自動引導(dǎo)將不會成功的此功能由環(huán)境（ENV）命令和在通電時（也可以在重置時）或通過RB命令執(zhí)行假設(shè)閃存中有有效代碼（或可選地在模塊或VMEbus）來支持它。如果安裝了ROMboot代碼，則會為用戶編寫的例程提供控制（如果例程滿足格式要求）。ROMboot的一個用途可能是在非智能設(shè)備上重置SYSFAIL*控制器模塊。NORB命令禁用該功能。為了讓用戶的ROMboot模塊通過ROMboot鏈接獲得控制，
必須滿足四個要求：1、必須剛剛通電（但ENV命令可以更改）這也會響應(yīng)任何重置）。2、用戶例程必須位于MVME197LE ROM內(nèi)存中映射（但ENV命令可以將其更改為車載內(nèi)存，甚至非車載VMEbus內(nèi)存）。3.ASCII字符串“BOOT”必須位于指定內(nèi)存中范圍
4.用戶的例程必須通過校驗和測試，以確保例行程序?qū)嶋H上是為了在通電時接受控制。
有關(guān)如何使用ROMboot的完整詳細信息，請參閱MVME197BUG197Bug調(diào)試包用戶手冊。
網(wǎng)絡(luò)引導(dǎo)網(wǎng)絡(luò)自動引導(dǎo)是包含在197Bug中的一個軟件例程，它可以提供使用網(wǎng)絡(luò)（本地）引導(dǎo)操作系統(tǒng)的機制
以太網(wǎng)接口）作為引導(dǎo)設(shè)備。網(wǎng)絡(luò)自動引導(dǎo)例程
Following this message there is approximately a thirty-second delay while the
debug firmware waits for the various controllers and drives to come up to
speed. Then the actual I/O is begun: the program pointed to within the
volume ID of the media specified is loaded into RAM and control passed to it.
If, however, during this time the user wants to gain control without Autoboot,
the <BREAK> key or the software ABORT or RESET switches can be pressed.
Autoboot is controlled by parameters contained in the ENV command. These
parameters allow the selection of specific boot devices and files, and allow
programming of the Boot delay. Refer to the ENV command in Appendix A for
more details.Although streaming tape can be used to autoboot, the same
power supply must be connected to the streaming tape
drive, controller, and the MVME197LE. At power-up, the
tape controller will position the streaming tape to load point
where the volume ID can correctly be read and used.
If, however, the MVME197LE loses power but the controller
does not, and the tape happens not to be at load point, the
sequences of commands required (attach and rewind)
cannot be given to the controller and autoboot will not be
successful.
ROMboot
This function is configured/enabled by the Environment (ENV) command and
executed at power-up (optionally also at reset) or by the RB command
assuming there is valid code in the flash memories (or optionally elsewhere on
the module or VMEbus) to support it. If ROMboot code is installed, a userwritten routine is given control (if the routine meets the format requirements).
One use of ROMboot might be resetting SYSFAIL* on an unintelligent
controller module. The NORB command disables the function.
For a user’s ROMboot module to gain control through the ROMboot linkage,
four requirements must be met:
1. Power must have just been applied (but the ENV command can change
this to also respond to any reset).
2. The user’s routine must be located within the MVME197LE ROM memory
map (but the ENV command can change this to any other portion of the
onboard memory, or even offboard VMEbus memory).
3. The ASCII string “BOOT” must be located within the specified memory
range.
4. The user's routine must pass a checksum test, which ensures that this
routine was really intended to receive control at power-up.
For complete details on how to use ROMboot, refer to the MVME197BUG
197Bug Debugging Package User’s Manual.
Network Boot
Network Auto Boot is a software routine contained in the 197Bug that
provides a mechanism for booting an operating system using a network (local
Ethernet interface) as the boot device. The Network Auto Boot routine
