Kontron VMP1 - Manual (Page 69)

VMP1 Bootstrap Loader
ID 19972, Rev. 0101 Page 5 - 3 ® PEP Modular Computers GmbH
5. Bootstrap Loader
The VMP1 Bootstrap Loader is a standalone software located in the Flash memory
which allows the user to safely update the contents of the Flash and delay the boot pro-
cess for a specified time.
The Bootstrap Loader has the capability to program Flash memory from “MOTOROLA
S-RECORDS” or from an absolute memory address. If the programmed image does not
work, the Bootstrap Loader can be re-entered. The memory contents can be examined
and another programming cycle initiated.
The Bootstrap Loader is delivered already installed in soldered Flash.
Please read this user manual before reprogramming any Flash memory.
5.1 System Operation
5.1.1 Startup
After system reset, the Bootstrap Loader is started. It searches the Flash memory area
for a valid start key. If this start key is found, the Bootstrap Loader checks the 'BootWait-
Time' from serial EEPROM. If the entry is valid, the continuation of the boot process is
delayed for a period during which the green front panel LED flashes to indicate that the
system is alive but waiting for continuation. If the entry is not valid, a default of 5 sec-
onds is used. After the BootWaitTime has passed, the program in Flash is downloaded
and started.
The Bootstrap Loader has two modes of operation: non-interactive start mode as
described above and the interactive command mode.
For normal board operation, only the non-interactive start mode is used to start a pro-
gram in Flash. This happens automatically without any user interaction. The interactive
command mode is used to re-program the Flash memory contents or change the Boot-
WaitTime.
The serial term port operates at 9600 Baud, 8 bits / character, 1 stop bit and no parity by
default.
!
Warning!
When programming Flash memory, please do not press the
RESET button or switch off the mains power under any cir-
cumstances! Doing so may damage the Bootstrap Loader and
would consequently leave the board unusable due to corrupt
Flash contents.
However, the ABORT button may be used to cancel a running
operation safely.