Artesyn ATCA-9305 User's Manual (May 2014) - Manual (Page 194)

System Management
ATCA-9305 User’s Manual (10009109-07) 194
The boot options need to be stored as a sequence of zero terminated strings. The following
table describes in detail the format of the boot options to be used when setting or reading the
System Boot Options parameter #100.
When writing to or reading from the storage area, you can only read ore write chunks of 16
bytes at a time. For this reason, the IPMC memory is divided into numbered blocks of 16 bytes
which need to be addressed individually. For this purpose the "block selector" field in the
request data field is used.
7.15 BOOT DEVICE REDIRECTION (BDR)
The IPMC enables the ATCA-9305 to recover from monitor corruption by booting from a
redundant copy in another flash device. The mechanism relies on an IPMC software internal
watchdog to expire when corrupted code fails to reset the timer. This watchdog begins
counting down as soon as the payload is power cycled or reset. If the timer expires
(approximately 30 seconds), the boot redirection will activate and the board will reset.
Following this automatic reset, IPMC will attempt to boot from the next flash device according
to
Figure 7-4 . This sequence will continue until a valid boot image clears the watchdog.
Table 7-42 Boot Options Format
Byte Description
0-1 Number of bytes used for boot parameters (LSB first)
The number of bytes must be calculated and written into these two bytes by the
software which writes into the storage area. The values 0x0000 and 0xFFFF indicate
that not data has been written to the storage area. If you are reading from the storage
area and you find any of these two values, your software should assume that no boot
firmware boot options have previously been written to the storage area.
2-n Boot parameters data
The boot parameters are stored as ASCII text with the following general format:
=
, where all name/value pairs are separated by a zero byte. The
end of the boot parameter data is indicated by two zero bytes. Allowed and supported
name/value pairs are blade-specific.
n+1 - n+2 16 bit checksum over the boot parameters data section (LSB first)