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Firmware Manager
================
This is firman, the Firmware Manager.
firman automatically downloads and installs boot firmware images such as
libreboot.
firman can download firmware from the following distributors:
* Libreboot project
* Libiquity
firman supports the following systems:
* Lenovo ThinkPad X200[1]
* Minifree Libreboot X200
* Libiquity Taurinus X200
[1]: If already running firmware (such as libreboot) without flash
region write protections enabled by the firmware or Flash
Descriptor and without the Intel Management Engine enabled
firman will ask which distributor (if a system has multiple firmware
distributors), download mirror, and firmware version to use. For
libreboot images with the GNU GRUB payload, firman will ask which
keyboard layout to use. For systems with the Intel ICH9, firman will
allow the MAC address of the Intel Gigabit Ethernet controller to be
changed.
User Interfaces
===============
firman provides two user interfaces: a command-line interface (CLI) and
a textual user interface (TUI).
The TUI is based on a small custom library to manipulate ECMA-48 (ANSI
X3.64) terminals with DEC extensions (i.e. terminals compatible with the
DEC VT100). This terminal manipulation library is tested to work with
the Linux console, XTerm, and graphical terminal emulators that use the
VTE library (such as GNOME Terminal and Xfce Terminal).
There is one known bug with VTE (observed with versions 0.28.2 and
0.34.9): the text and background colors suddenly change after any key is
pressed while the last item of a menu dialog is selected. Clearing the
terminal (as is done when the next dialog is drawn) resolves the
problem.
Design Rationale
================
firman has two main goals: a user friendly interface and a small program
size.
Language Choice
---------------
firman needs to run a number of executable programs, including flashrom
and ich9gen. This means building argument vectors, creating pipes,
forking child processes, duplicating file descriptors, and executing
files. It also needs to download (e.g. via the libcurl library or a
wget executable) and verify (e.g. via an embedded SHA-512 implementation
or a sha512sum executable) files.
A C program can certainly do all of this reasonably well. But working
with child processes, pipes, and file descriptors are things that can be
done with less code in shell command language than in C. Additionally,
a BusyBox system is highly likely to already have a shell interpreter,
(small) wget executable, and sha512sum executable, so using libcurl or
an embedded SHA-512 implementation can increase the size of a small
embedded system.
Therefore, writing firman in shell command language actually makes it
smaller than writing it in C would.
Terminal Manipulation Library
-----------------------------
A user friendly interface is one with visual elements, or widgets.
Users are generally more familiar with dialog boxes, menus, text fields,
and buttons than they are with command line prompts. So firman offers a
textual user interface (TUI) in addition to a basic command line
interface (CLI).
Most TUI applications written in C or C++ use a common terminal
manipulation library (such as GNU Ncurses) that implements curses or a
similar API. Other languages often have native libraries or executables
to allow applications to use such a terminal manipulation library. Most
TUI applications written in shell command language use either dialog or
whiptail.
dialog is a somewhat large executable that uses GNU Ncurses (which isn't
very small either). Together, dialog and Ncurses take a few hundred
kibibytes of space. The whiptail executable and its Newt library are
smaller than dialog and Ncurses are, but Newt and dialog depend on the
huge S-Lang library. Newt, whiptail, and S-Lang combined weigh in at
well over a mebibyte.
firman's terminal manipulation library (term.sh) and TUI module, on the
other hand, total only about 15 KiB. Plus, shell command language
programs compress much better than compiled binaries do; firman's
term.sh and TUI module can be compressed down to under 4 KiB.
Copyright Information
=====================
Copyright (C) 2015 Patrick "P. J." McDermott
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved. This file is offered as-is,
without any warranty.
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