User`s manual

General Information
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1
During the delay, you can gain control without Network Autoboot
by pressing either the BREAK key or the software abort or reset
switches.
Network Autoboot is controlled by parameters contained in the
NIOT and ENV commands. These parameters allow the selection
of specific boot devices, systems, and files and allow programming
of the boot delay. Refer to the NIOT and ENV commands in
Chapter 3 for more details.
Restarting the System
You can initialize the system to a known state in three different
ways: reset, abort, and break. Each has characteristics which make
it more appropriate than the others in certain situations.
Reset
Pressing and releasing the board front panel RESET switch initiates
a system reset. Cold and warm reset modes are available. By
default, PPCBug is in cold mode (refer to the RESET command
description in Chapter 3). During cold reset, a total system
initialization takes place, as if the PowerPC board had just been
powered up. All static variables are restored to their default states.
The breakpoint table and offset registers are cleared. The target
registers are invalidated. Input and output character queues are
cleared. Onboard devices are reset, and the first two serial ports are
reconfigured to their default state.
During warm reset, the PPCBug variables and tables are preserved,
as well as the target state registers and breakpoints.
Reset must be used if the processor ever halts, or if the PPCBug
environment is ever lost, such as if the vector table is destroyed, or
the stack is corrupted.