LPF240A工控卡件,HITACHI使用過(guò)程
網(wǎng)絡(luò)引導(dǎo)控制模塊的“控制”能力需要與將所有必要的模塊（功能）放在一起，并對(duì)引導(dǎo)進(jìn)行排序過(guò)程引導(dǎo)序列包括兩個(gè)階段：第一階段標(biāo)記為“地址確定和引導(dǎo)文件選擇”，第二階段標(biāo)記為“文件傳輸”。第一階段將利用RARP/BOOTP功能和第二階段將利用TFTP能力。網(wǎng)絡(luò)輸入/輸出錯(cuò)誤代碼如果嘗試的網(wǎng)絡(luò)操作失敗，197Bug將返回錯(cuò)誤代碼不成功的多處理器支持MVME197LE雙端口RAM功能使共享RAM可用于遠(yuǎn)程處理器以及本地處理器。
LPF240A工控卡件這可以通過(guò)以下方式實(shí)現(xiàn)：以下兩種方法之一。任何一種方法都可以通過(guò)ENV命令作為其遠(yuǎn)程啟動(dòng)開(kāi)關(guān)方法（參考附錄A）。多處理機(jī)控制寄存器（MPCR）方法遠(yuǎn)程處理器可以在本地MVME197LE中啟動(dòng)程序執(zhí)行雙端口RAM，通過(guò)使用多處理器發(fā)出遠(yuǎn)程GO命令控制寄存器（MPCR）。MPCR位于3000美元的共享RAM位置從調(diào)試器加載它的基址的偏移量，包含兩個(gè)用于控制處理器之間通信的文字。MPCR內(nèi)容組織如下：多處理器地址寄存器（MPAR），位于共享RAM中調(diào)試器加載它的基址的3004美元偏移量的位置，包含兩個(gè)字中的第二個(gè)字，用于控制處理器之間的通信。MPAR內(nèi)容指定遠(yuǎn)程執(zhí)行的地址如果MPCR包含G或B，則處理器開(kāi)始。MPAR組織為通電后，調(diào)試監(jiān)視器自檢例程初始化RAM，包括用于多處理器支持的內(nèi)存位置。MPCR在通電時(shí)包含$00，表示尚未初始化完成隨著初始化的進(jìn)行，執(zhí)行路徑到達(dá)“提示”例程。在發(fā)送提示之前，此例程在MPCR指示初始化完成。然后發(fā)送提示。如果沒(méi)有終端連接到端口，則仍會(huì)輪詢MPCR以查看是否外部處理器需要將控制傳遞給雙端口RAM。如果a終端沒(méi)有響應(yīng)，MPCR被輪詢用于相同的目的，而正在輪詢串行端口以供用戶輸入。
Network Boot Control Module
The “control” capability of the Network Boot Control Module is needed to tie
together all the necessary modules (capabilities) and to sequence the booting
process. The booting sequence consists of two phases: the first phase is labeled
“address determination and bootfile selection” and the second phase is labeled
“file transfer”. The first phase will utilize the RARP/BOOTP capability and the
second phase will utilize the TFTP capability.
Network I/O Error Codes
197Bug returns an error code if an attempted network operation is
unsuccessful.
Multiprocessor Support
The MVME197LE dual-port RAM feature makes the shared RAM available to
remote processors as well as to the local processor. This can be done by either
of the following two methods. Either method can be enabled/disabled by the
ENV command as its Remote Start Switch Method (refer to Appendix A).
Multiprocessor Control Register (MPCR) Method
A remote processor can initiate program execution in the local MVME197LE
dual-port RAM by issuing a remote GO command using the Multiprocessor
Control Register (MPCR). The MPCR, located at shared RAM location of $3000
offset from the base address the debugger loads it at, contains one of two
words used to control communication between processors. The MPCR
contents are organized as follows:The Multiprocessor Address Register (MPAR), located in shared RAM
location of $3004 offset from the base address the debugger loads it at, contains
the second of two words used to control communication between processors.
The MPAR contents specify the address at which execution for the remote
processor is to begin if the MPCR contains a G or B. The MPAR is organized as
followsAt power up, the debug monitor self-test routines initialize RAM, including
the memory locations used for multi-processor support ($3000 through $3007).
The MPCR contains $00 at power-up, indicating that initialization is not yet
complete. As the initialization proceeds, the execution path comes to the
“prompt” routine. Before sending the prompt, this routine places an R in the
MPCR to indicate that initialization is complete. Then the prompt is sent.
If no terminal is connected to the port, the MPCR is still polled to see whether
an external processor requires control to be passed to the dual-port RAM. If a
terminal does respond, the MPCR is polled for the same purpose while the
serial port is being polled for user input.
