shithub: purgatorio

ref: 75c92428225428c8fde2d015f010e608a0b12f1d
dir: /os/boot/README/

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Often the devices we use now come with some
form of bootstrap (often annoyingly complicated,
which gets in the way).  Older boards were sometimes
bare, and we had to provide something (often annoyingly
complicated...).  On the PC it's currently helpful to
have something that can boot from disc or ether;
since it's a thankless task to write such a thing, we
use Plan 9's, and thank its authors.

The current scheme on newer devices is to have a simple
program that can put a stripped-down Inferno kernel into
flash, and use that to boot from other devices (including over the net)
as required during development.

There are two distinct models for bootstrap in this directory.

	Model I

Each member of the first model is represented by a self-contained directory.
They are derived from various ages of Plan 9's /sys/src/boot/pc.

arm1110	arm	a prefix to a gzip'd kernel to decompress it (runs after basic bootloader)
pc	386	pc-specific bootstrap essentially identical to current Plan 9
		and covered by the Lucent Public License; it uses
libflate	-	zlib-style inflate/deflate library
mpc	power	PowerPC bootstrap for FADS board derived from an older version
		of Plan 9 but covered by our Inferno licence (because it came with Inferno)
puma	arm	SA110 bootstrap for Teralogics Puma, also covered by the Inferno licence

	Model II
omap	purpose-built bootstrap for the OMAP processor

Not all of these are being distributed.