I loaded the 1.2.1 source balls and tried to make a new kernel:

cc  -O2 -Werror -Wall -Wstrict-prototypes -Wmissing-prototypes -mno-fpu -I. -I../../../../arch -I../../../.. -DSUN4M -DTIMEZONE="0x1e0" -DDST="1" -DSWAPPAGER -DVNODEPAGER -DDEVPAGER -DKTRACE -DSYSVMSG -DSYSVSEM -DSYSVSHM -DLKM -DUCONSOLE -DDDB -DDIAGNOSTIC -DKGDB -DCOMPAT_43 -DCOMPAT_10 -DCOMPAT_11 -DCOMPAT_SUNOS -DCOMPAT_SVR4 -DFFS -DQUOTA -DNFSSERVER -DNFSCLIENT -DKERNFS -DNULLFS -DMFS -DFDESC -DPROCFS -DCD9660 -DUNION -DFIFO -DINET -DTCP_COMPAT_42 -DGATEWAY -DRASTERCONSOLE -DXSERVER -DBLINK -D_KERNEL  -c ../../../../arch/sparc/dev/bwtwo.c
../../../../arch/sparc/dev/bwtwo.c: In function `bwtwoattach':
../../../../arch/sparc/dev/bwtwo.c:328: structure has no member named `sc_ovtype'
../../../../arch/sparc/dev/bwtwo.c:328: `BWO_NONE' undeclared (first use this function)
../../../../arch/sparc/dev/bwtwo.c:328: (Each undeclared identifier is reported only once
../../../../arch/sparc/dev/bwtwo.c:328: for each function it appears in.)
*** Error code 1
 
Stop.

The offending code is

#ifdef RASTERCONSOLE
		if (sc->sc_ovtype == BWO_NONE)
			fbrcons_init(fb);
#endif

Since the PATCHLEVEL file that came with the 1.2.1 sources says

	[ kernel/sparc ] Disable rcons on the bwtwo, since it doesn't work yet.

I suspect this is an artifact of those changes which slipped through ...

I'll work around it by disabling the bwtwo0 in the config file (since
my SS20 doesn't have one anyway), but just thought I'd mention it ...

	- Greg