There are two basic methods of acquiring kernel sources. The first method is to download a gzipped tar file from a standard release. This is the method for those who are doing anything but "bleeding edge" kernel development. The second method is to "sup" or otherwise get the current files from sup.netbsd.org or ftp.netbsd.org on a regular basis.
For the first method, download the ksrc file from a NetBSD/mac68k distribution site and extract it according to the directions for that release (usually in the INSTALL document).
A quick road map to the source is the subject of the next section .
The second method requires more dedication and adventure. The current sources are not guaranteed to run, or even compile, at any given time. There are several way to accomplish this task. With a direct internet connection, it is possible to use the CMU sup(1) utility to retrieve the changes daily. This is certainly the least work. See the supkit for instructions on how to set this up. The supkit can be obtained from NetBSD/mac68k distribution sites.
Without a direct internet connection, it is necessary to get the files by hand. The safest way is to get the entire sys tree at once:
ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-current/tar_files/src/sys.tar.gz
tar xvzf sys.tar.gz
Individual files can be obtained from the source tree:
ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-current/src/sys/
...
This is a very general overview of what is in most of the kernel source directories.
src/
sys/ - Kernel source top level
arch/ - Architecture specific directories
alpha/ - DEC Alpha-based systems
amiga/ - Commodore Amiga systems (m68k)
arm32/ - Acorn RiscPC machines
atari/ - Atari TT/Falcon systems (m68k)
hp300/ - HP 300-series systems (m68k)
i386/ - Intel 80x86 systems
m68k/ - Generic code shared between the m68k platforms
include/ - This becomes /usr/include/m68k
mac68k/ - 68K Macintosh-specific code
dev/ - Device drivers
include/ - This becomes /usr/include/machine
mac68k/ - General machine dependent files. Like locore/trap/etc
conf/ - Configuration directory
scsi/ - The SCSI subsystem. This should eventually be sys/scsi
compile/ - Configured kernels are built here
GENERIC/ - A generic kernel
mvme68k/ - Motorola 68k-based VME boards (m68k)
pc532/ - NS32532-based net-brew systems
pica/ - Acer Pica systems
pmax/ - DEC MIPS-based DECStations
powerpc/ - PowerPC-based Open Firmware systems
sparc/ - Sun sparc-based systems
sun3/ - Sun3-series systems (m68k)
vax/ - DEC VAX systems
x68k/ - Sharp X680x0 systems
compat/ - Compatibility code for SunOS, Linux, SVR4 and others
conf/ - Machine-independent configuration directory
ddb/ - Machine-independent code for the kernel debugger
dev/ - Device drivers that aren't tied to specific architectures
kern/ - Core kernel functions
lib/ - Kernel, compat, and standalone libraries
lkm/ - Loadable Kernel Module code
*fs/ - Code for various filesystems
net*/ - Networking stuff
nfs/ - Network File System
scsi/ - Machine-independent scsi system
sys/ - Becomes /usr/include/sys
vm/ - Machine-independent virtual memory code
Traditionally, BSD systems have had a program called "config" to take a configuration file as input and generate a Makefile with which you build a kernel. 4.4 BSD has generalized the machine-specific nature of this older system.
Like the older config, this new config uses a configuration file. SYSTEM shall be used in this description, but GENERIC, BASIC, and EARWIG are equally acceptable names. GENERIC has some special meaning, though, as we shall see later. Various options and drivers are specified, and std.mac68k is included from this file for the basic devices. See the Options section for a brief summary of some of the more common options. Getting a working system configuration file from scratch can be a frustrating experience, so it's recommended that new configurations be derived from existing files.
Config for NetBSD/mac68k uses the following files for information:
sys/arch/mac68k/conf/SYSTEM
sys/arch/mac68k/conf/std.mac68k
sys/arch/mac68k/conf/files.mac68k
sys/arch/mac68k/conf/Makefile.mac68k
sys/arch/m68k/conf/files.m68k
sys/conf/files
For example, assume joe_blow@earwig has the sources extracted in his home directory:
joe@earwig:~/sys/arch/mac68k/conf % config SYSTEM Don't forget to run "make depend" joe@earwig:~/sys/arch/mac68k/conf %
Please note that you need to be using a version of config which
matches your sources. The format of the configuration file tends to change
slightly between releases, so it is a good idea to compile your own copy of
config before you begin to configure your own kernel.
Simply change directory to the directory that config created or updated in step 2 and type "make depend ; make".
Continuing the example from above:
joe@earwig:~/sys/arch/mac68k/conf % cd ../compile/SYSTEM joe@earwig:~/sys/arch/mac68k/compile/SYSTEM % make depend ; makeThis step for the GENERIC configuration takes about 1.5 hours on an SE/30 with 8MB that is otherwise idle. Speeding it up is work-in-progress.
Simply copy the kernel into the root directory and reboot. In case there is a problem with the new kernel, do not copy it to /netbsd. Use /netbsd.test or something like that. Then, in the "Booting..." dialog of the booter, specify the test kernel's name. After the kernel boots successfully, move /netbsd to /netbsd.old or /netbsd.bak and move the new netbsd.test to /netbsd. In general, the following naming conventions are useful:
/netbsd -- Current kernel. This is necessary for
programs like ps and w that need to read
information from /netbsd.
/netbsd.test -- Test kernel. Temporary.
/netbsd.dist -- Last distributed kernel. Hopefully known
to work.
/netbsd.last -- Last custom kernel that has been used for
some time and is known to work.
/onetbsd -- An old kernel as a backup in case everything
else fails.
Next Chapter, Previous Chapter
Table of contents of this chapter, General table of contents
Top of the document, Beginning of this Chapter