Sun Microsystems StorEdge T3+, Service Manual

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4-8 Sun StorEdge T3 and T3+ Array Field Service Manual • September 2001
4.3.2 Sun StorEdge T3+ Array Controller Firmware
4.3.2.1 Boot Code Explanation
There are three levels of boot code.
■
The first level selects and jumps to one of the two copies of the second level code.
The second level code initializes memory and loads itself to RAM locations
starting from 0x500000.
■
The second level code can allow tftp boot or ROM boot for the third level code. In
ROM boot, the second level code selects one of the two copies of the third level
(RAID application) code. The second level code loads the RAID application code
to RAM locations from 0x20000.
■
The third level is the RAID application.
First Level Boot Code
The level 1 boot code starts at 0xFFF00100 which is the processor’s reset vector. The
first level code initializes the MPC107 bridge chip and the console serial port. It
prints
T3B-
when the initialization is done. Then it waits about 1.5 seconds to allow
the user to select one of the two copies of level 2 code to boot. The user can type
1
or
2
, but there is no echo for the character typed. If the user makes no selection, level 2
code does the selection automatically.
In the automatic selection, the level 1 code verifies the level 2 boot code stored in
ROM. It finds which one is newer and jumps to the selected code.
If the user has entered the selection before automatic selection, level 1 code jumps to
the one the user has selected after verifying the code is valid. If the user selects an
invalid copy, then level 1 code jumps to the valid one instead of the user selected
one.
After the level 1 code has decided which copy of level 2 code to use, it prints
1
or
2
to notify the user which copy is selected as a feedback.
The level 1 code starts at 0xFFF00100 and extends to 0xFFF20000.
If there is no valid level 2 code, the code prints
0
after
T3B-
and reboot.