Based on b98, added missing virtual drivers – now you can boot MilaX iso in Guest LDom.
Thanks to Jim Walker for sparc access and special thanks to Bernd Schemmer for LDom tests.

Sample LDom output from Bernd:

{0} ok boot /virtual-devices@100/channel-devices@200/disk@5

SPARC Enterprise T5220, No Keyboard
Copyright 2008 Sun Microsystems, Inc. All rights reserved.
OpenBoot 4.29.0, 28672 MB memory available, Serial #######.
Ethernet address #########, Host ID: ########.

Boot device: /virtual-devices@100/channel-devices@200/disk@5 File and args:
SunOS Release 5.11 Version MilaX_0.3.2 64-bit
Copyright 1983-2008 Sun Microsystems, Inc. All rights reserved.
Use is subject to license terms.
Remounting root read/write
Probing for device nodes …
Preparing live image for use
Hostname: milax
Done mounting live image from memory
Configuring devices.
Mounting local partitions/cdroms
Using physical swap on hdd (/dev/dsk/c1d0s1)
Reading ZFS config: done.

milax console login: alex
Password:

Sun Microsystems Inc. SunOS 5.11 MilaX_0.3.2 October 2008
(alex@milax)$ df -k
Filesystem kbytes used avail capacity Mounted on
/devices/ramdisk-root:a
81659 72208 1286 99% /
/devices 0 0 0 0% /devices
/dev 0 0 0 0% /dev
ctfs 0 0 0 0% /system/contract
proc 0 0 0 0% /proc
mnttab 0 0 0 0% /etc/mnttab
swap 28201616 1296 28200320 1% /etc/svc/volatile
objfs 0 0 0 0% /system/object
sharefs 0 0 0 0% /etc/dfs/sharetab
/dev/dsk/c1d5s0 220460 220460 0 100% /.cdrom
swap 28332920 132600 28200320 1% /tmp
/dev/lofi/1 348194 348194 0 100% /usr
df: cannot statvfs /platform/sun4v/lib/libc_psr.so.1: Operation not
applicable
df: cannot statvfs /platform/sun4v/lib/sparcv9/libc_psr.so.1: Operation
not applicable
fd 0 0 0 0% /dev/fd
/dev/dsk/c1d0s0 20658289 14748562 5703145 73% /mnt/solaris0
/dev/dsk/c1d0s3 4131198 505218 3584669 13% /mnt/solaris1
/dev/dsk/c1d0s4 8263157 8218 8172308 1% /mnt/solaris2
/dev/dsk/c1d0s5 2055271 2244 1991369 1% /mnt/solaris3
/dev/dsk/c1d0s6 2055271 2110 1991503 1% /mnt/solaris4
/dev/dsk/c1d2s0 17554706 2066433 15312726 12% /mnt/solaris5
/dev/dsk/c1d2s2 1016399 1041 954375 1% /mnt/solaris6
/dev/dsk/c1d2s3 1016399 1041 954375 1% /mnt/solaris7
/dev/dsk/c1d4s0 18588482 18449 18384149 1% /mnt/solaris8
swap 28200376 56 28200320 1% /var/run
swap 28200368 48 28200320 1% /root
swap 28200368 48 28200320 1% /alex
(alex@milax)$

(alex@milax)$ ifconfig -a
lo0: flags=2001000849 mtu
8232 index 1
inet 127.0.0.1 netmask ff000000
vnet0: flags=201004843 mtu
1500 index 2
inet 0.0.0.0 netmask ff000000
vnet1: flags=201000843 mtu 1500
index 3
inet 0.0.0.0 netmask ff000000 broadcast 0.255.255.255
vnet2: flags=201000843 mtu 1500
index 4
inet 0.0.0.0 netmask ff000000 broadcast 0.255.255.255
vnet3: flags=201000843 mtu 1500
index 5
inet 0.0.0.0 netmask ff000000 broadcast 0.255.255.255
lo0: flags=2002000849 mtu
8252 index 1
inet6 ::1/128
(alex@milax)$

(alex@milax)$ uname -a
SunOS milax 5.11 MilaX_0.3.2 sun4v sparc SUNW,SPARC-Enterprise-T5220
(alex@milax)$