NetBootLoader
VMP2
Page 5 - 12
© 2002 PEP Modular Computers GmbH
ID 24855, Rev. 02
5.4.7
Uploading a FLASH Area
The NetBootLoader also has the possibility to upload certain areas of the FLASH to a host us-
ing the Ethernet interface. To use this interface the Ethernet parameters must first be set and
then the system must be restarted. During boot wait the operator must gain control of the Net-
BootLoader and perform an ftp server login. After a successful login, the operator then stores
the FLASH area to be uploaded to the local data buffer using the “sf” command. Using the “put”
command transfers the contents of the data buffer to the ftp server. As with any type of server
session, the operator should logout when the session is finished.
5.5
Plug and Play
On the CPU board the NetBootLoader includes “Plug and Play” functionality. This ensures that
the board is completely initialized and that all resources necessary for PCI devices (addresses,
interrupts etc.) are assigned automatically. This important feature has the advantage that con-
flicts do not arise when PCI devices are added or removed. Furthermore, the operating system
itself does not include the board initialization code.
5.6
Porting an Operating System to the CPU Board
The image for the absolute address 0x0 should be linked with an entry point at the absolute
address 0x100.
One should not attempt to reassign the PCI BAR registers. The assigned values should be read
back and these should always be used in the drivers.
The “interrupt line” field in the PCI configuration header is initialized with the IRQ line number
to which the INTA of the device is routed.
It is not necessary to rewrite the “EUMBBAR” field in the KAHLUA (MPC 8240) configuration
space as this has already been done by the NetBootLoader. The existing value should be used.
Downloaded images are never executed from the FLASH due to the fact that on the CPU board
it is paged. The programmed image is always downloaded to SDRAM, the absolute address
0x0 being downloaded first. There is no configuration option available to amend this process.
If it is necessary to relocate the image to another address after download, simply add a small
assembly routine at the beginning of the code which will move the image to the correct address.
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