ref: b5bc6572b0a82c52ab04bcf25e1ed76700deb246
dir: /INSTALL/
Installing hosted Inferno from source
Overview
Like the native kernels emu relies on several auxil-
iary libraries (the source of which it often shares with the
native kernels). Emu itself is built by the mkfile in the
emu subdirectory containing the platform-specific source for
the host platform. Each library has its own mkfile; the
various components are made in the right order by the
mkfile at the root of the Inferno tree. The mkfile for
each platform will also invoke mk recursively to make the
appropriate libraries for a given configuration.
The Unix emu variant generally is covered by `POSIX'
(with common extensions) but each Unix port has one file
that differs considerably for each port, namely
emu/platform/os.c, the differences corresponding to the dif-
ferent ways under Unix of implementing kernel-scheduled
threads efficiently.
There are working emu versions for FreeBSD/386,
Irix/mips, Linux/386, NetBSD/386, MacOSX/386, MacOSX/power,
Plan 9, Solaris/sparc, and Windows (NT, 2000 and Explorer
plug-in). Each platform typically uses mechanisms specific
to the host operating system to implement Inferno's internal
thread/process structure. POSIX threads have often been
found to be insufficient (poorly implemented) on some plat-
forms, and if so are avoided. See kproc in emu/*/os.c.
Source is included for ports to HP/UX (S800 architec-
ture), Solaris/386, and Unixware, in case someone wishes to
take them up now, but we have not determined their fitness.
The Plan 9 hosted implementation is unusual in that it
supports several processor types: 386, mips, power (Power
PC) and sparc. Furthermore, all versions of emu can be
built on any processor type, in the usual way for Plan 9.
Otherwise, as distributed, emu for a platform can only
be built when running on that platform.
One unusual variant makes the whole of Inferno a plug-
in for Microsoft's Internet Explorer, giving the same envi-
ronment for Inferno applications running in an HTML page as
is provided by hosted or native Inferno. That is, there is
not a distinct `applet' environment with special programming
interfaces. The source for the various plug-in components
is found in /tools/plugin and /usr/internet within the
Inferno tree; they use the version of emu defined by the
configuration file /emu/Nt/ie.
Build steps
All the libraries and executables can be built in a
tree containing only the source code. To do that for a sup-
ported variant of hosted Inferno, on Unix or Plan 9, do the
following in the root of the Inferno tree:
1 Edit mkconfig to reflect your host environment,
specifically ROOT (which must be an absolute path
name), SYSHOST and OBJTYPE. The comments in the file
should help you choose.
2 Run makemk.sh to rebuild the mk command, which is
used to build everything else.
3 Set PATH (or path on Plan 9) to include the bin
directory for the platform, which will now contain the
mk binary just built. On Unix, export PATH.
4 Then mk nuke to remove any extraneous object files.
5 Finally, mk install to create and install the
libraries, limbo compiler, emu for hosted Inferno,
and auxiliary commands. The rules do that in an order
that ensures that the commands or libraries needed by a
later stage are built and installed first. (Note that
a plain mk will not suffice, because it does not put
the results in the search path.)
Doing something similar on Windows or Plan 9 currently
requires the executable for mk to be available in the
search path, since there is no equivalent of makemk.sh.
Otherwise the procedure is the same. On Plan 9, of course,
the host system's normal version of mk should be adequate.