1. New computer hardware, unadorned with such snares and
assembler. Commonly used in the phrase "programming on the
bare metal", which refers to the arduous work of
bit bashingneeded to create these basic tools for a new computer. Real
bare-metal programming involves things like building
bootPROMs and
BIOS chips, implementing basic
monitors used to
used to write the compiler back ends that will give the new
computer a real development environment.
2. "Programming on the bare metal" is also used to describe a
style of
hand-hacking that relies on bit-level peculiarities
of a particular hardware design, especially tricks for speed
and space optimisation that rely on crocks such as overlapping
instructions (or, as in the famous case described in
TheStory of Mel, interleaving of opcodes on a magnetic drum to
minimise fetch delays due to the device's rotational latency).
This sort of thing has become less common as the relative
costs of programming time and computer resources have changed,
but is still found in heavily constrained environments such as
industrial embedded systems, and in the code of hackers who
In the world of personal computing, bare metal programming is
often considered a
Good Thing, or at least a necessary evil
(because these computers have often been sufficiently slow and
poorly designed to make it necessary; see
ill-behaved).
There, the term usually refers to bypassing the BIOS or OS
interface and writing the application to directly access
device registers and computer addresses. "To get 19.2
kilobaud on the serial port, you need to get down to the bare
metal." People who can do this sort of thing well are held in
high regard.