====== Building FreeBSD-MIPS ======

===== General build instructions =====

You will need the proper MACHINE_ARCH that encodes ABI and endian information.  Please see the following table for which to select.  For 32-bit MIPS platforms (or to run a 32-bit kernel on a 64-bit CPU) use mipsel or mips, while 64-bit MIPS platforms will use mips64el or mips64.  The 'el' variety is used for machines with little endian byte order, while big endian byte order is implicit otherwise.

| Byte | ABI |||
| Order | o32 | n32 | n64 |
| Little | mipsel | mipsn32el | mips64el |
| Big | mips | mipsn32 | mips64 |

You will set TARGET to 'mips' below and TARGET_ARCH to the entry from the table above.

Here are a few examples of TARGET_ARCH:

| System | TARGET_ARCH | System endianness and ABI |
| MALTA (gxemul) | mipsel | o32 little endian |
| rt305x | mipsel | o32 little endian |
| AR71xx/AR93xx | mips | o32 big endian |
| Octeon/ERL | mips64 | n64 big endian |

Choose the kernel you want to build and then use something like this script (the omissions are for size or speed of build reasons only):

<code>
#!/bin/csh

setenv SRCROOT /home/gonzo/FreeBSD/svn/mips
setenv TARGET mips
setenv TARGET_ARCH mipsel
# not used:
# setenv TARGET_CPUTYPE mips32
setenv KERNCONF MALTA
setenv MAKEOBJDIRPREFIX /home/gonzo/FreeBSD/obj/mips
set NFSROOT=/home/gonzo/FreeBSD/nfsroot
set TFTPBOOT=/tftpboot

# Select some subset: the following used to be good, but now isn't
# set MAKEFLAGS=(-DWITHOUT_CDDL           \
#                -DWITHOUT_GAMES         \
#                -DWITHOUT_DOCS          \
#                -DWITHOUT_ACPI          \
#                -DWITHOUT_KERBEROS      \
#                -DWITHOUT_RESCUE        \
#                -DWITHOUT_MAN           \
#                -DWITHOUT_PROFILE       \
#                -DWITHOUT_BSNMP         \
#                -DWITHOUT_NIS           \
#                -DWITHOUT_IPX           \
#                -DWITHOUT_ATM)

cd ${SRCROOT}
make ${MAKEFLAGS} kernel-toolchain
make ${MAKEFLAGS} buildkernel
make ${MAKEFLAGS} DESTDIR=${TFTPBOOT} installkernel
make ${MAKEFLAGS} buildworld

sudo -E make DESTDIR=${NFSROOT} ${MAKEFLAGS} installworld
sudo -E make DESTDIR=${NFSROOT} ${MAKEFLAGS} distribution
</code>

===== Boot =====
There is no ready-for-use firmware yet so you'll need either netboot your board and mount root over NFS. Or build disk image for emulator (like gxemul).

==== Netboot ====
  * Setup isc-dhcpd and add entry for board (config courtesy of Andrew Thompson)

<code>

subnet 192.168.10.0 netmask 255.255.255.0 {
	deny unknown-clients;
	option routers 192.168.10.1;
	option root-path "192.168.10.196:/src/nfsroot";
	# tftp server address and kernel path
	next-server 192.168.10.196;
	filename "kernel";
}

host mips {
	hardware ethernet 00:15:6d:c1:28:2e;	# the mac address of the board
	fixed-address 192.168.10.x;		# pick an unused address
}
</code>

  * Enable tftpd in inetd.conf, modify -s parameter to point to directory with MIPS kernels and restart inetd

<code>
tftp    dgram   udp     wait    root    /usr/libexec/tftpd      tftpd -l -s /src/FreeBSD/tftpboot
</code>

  * Add $DESTDIR entry to /etc/exports

<code>
$DESTDIR -maproot=root -network 192.168.10/24
</code>

  * Add root fs to $DESTDIR/etc/fstab

<code>
192.168.10.196:/src/nfsroot     /       nfs     rw      0       0

</code>

  * Enable mountd/nfsd (and optionally rpc.statd/rpc.lockd) in /etc/rc.conf and start them

<code>
rpcbind_enable="YES"
rpc_statd_enable="YES"
rpc_lockd_enable="YES"
nfs_server_enable="YES"
mountd_enable="YES"
</code>

==== GXEmul ====
  * Add line for root fs to $DESTDIR/etc/fstab 
  * Build proper image using makefs tool (sysutils/makefs):

<code>
makefs mips.img $DESTDIR
</code>

  * Boot gxemul (with GXEMUL kernel configuration): 

<code>
gxemul -E oldtestmips -d i:/path/to/mips.img /path/to/kernel
</code>

  * Boot gxemul (with Malta kernel configuration): 

<code>
gxemul -e malta -d i:/path/to/mips.img -C 4Kc /path/to/kernel
</code>