Comtrol eCos - Manual (Page 107)

Chapter 1. Getting Started with RedBoot
• ^P replaces the current line by a previous line from the history buffer. A small number of lines can be kept as
history. Using ^P (and ^N), the current line can be replaced by any one of the previously typed lines.
• ^N replaces the current line by the next line from the history buffer.
In the case of the fconfig command, additional editing commands are possible. As data are entered for this com-
mand, the current/previous value will be displayed and the cursor placed at the end of that data. The user may
use the editing keys (above) to move around in the data to modify it as appropriate. Additionally, when certain
characters are entered at the end of the current value, i.e. entered separately, certain behavior is elicited.
• ^ (caret) switch to editing the previous item in the fconfig list. If fconfig edits item A, followed by item B,
pressing ^ when changing item B, allows you to change item A. This is similar to the up arrow. Note: ^P and ^N
do not have the same meaning while editing fconfig data and should not be used.
• . (period) stop editing any further items. This does not change the current item.
• Return leaves the value for this item unchanged. Currently it is not possible to step through the value for the
start-up script; it must always be retyped.
RedBoot Startup Mode
RedBoot can normally be configured to run in a number of startup modes (or just "modes" for short), determining
its location of residence and execution:
ROM mode
In this mode, RedBoot both resides and executes from ROM memory (flash or EPROM). This mode is used
when there are limited RAM resources. The flash commands cannot update the region of flash where the
RedBoot image resides. In order to update the RedBoot image in flash, it is necessary to run a RAM mode
instance of RedBoot.
ROMRAM mode
In this mode, RedBoot resides in ROM memory (flash or EPROM), but is copied to RAM memory before it
starts executing. The RAM footprint is larger than for ROM mode, but there are two advantages to make up
for this: it normally runs faster (relevant only on slower boards) and it is able to update the flash region where
the image resides.
RAM mode
In this mode, RedBoot both resides and executes from RAM memory. This is used for updating a primary
ROM mode image in situ and sometimes as part of the RedBoot installation on the board when there’s already
an existing (non-RedBoot) boot monitor available.
You can only use ROM and ROMRAM mode images for booting a board - a RAM mode image cannot run
unless loaded by another ROM monitor. There is no need for this startup mode if a RedBoot ROMRAM mode
image is the primary boot monitor. When this startup mode is programmed into flash (as a convenience as it’s
fast to load from flash) it will generally be named as "RedBoot[RAM]" in the FIS directory.
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