Trying to reach 1993

Trying to boot yet older Solaris/SunOS version: Solaris 2.3. According to the Wikipedia, it's the first one which supported SPARCStation-5. You may wanna ask "what is about SunOS 4.1.4 (Solaris 1.1.2), it can be booted, and it must be the older?". No, it's not. Looks like Solaris 2.x and SunOS 4.x were developed independently: 1.1.2 was released in November 1994, and 2.3 was released in November 1993. Is a bit misleading. But explains why 2.3 has problems with the esp scsi controller while 1.1.2 doesn't. And the both systems are so old that the kadb debugger can't set deferred breakpoints. Anyway, the current status of Solaris 2.3:

ok boot disk1:d -vs
Boot device: /iommu/sbus/espdma@5,8400000/esp@5,8800000/sd@1,0:d  File and args: -vs
Size: 719688+166144+108728 Bytes
SunOS Release 5.3 Version Generic [UNIX(R) System V Release 4.0]
Copyright (c) 1983-1993, Sun Microsystems, Inc.
vac: enabled in write through mode
cpu0: FMI,MB86907 (mid 0 impl 0x0 ver 0x4 clock 1075 MHz)
mem = 65536K (0x4000000)
avail mem = 58142720
Ethernet address = 52:54:0:12:34:56
root nexus = SUNW,SPARCstation-5
iommu0 at root: obio 0x10000000
sbus0 at iommu0: obio 0x10001000
espdma0 at sbus0: SBus slot 5 0x8400000
esp0 at espdma0: SBus slot 5 0x8800000 sparc ipl 4
        polled command timeout
esp:            State=CLEARING Last State=CLEARING
esp:            Latched stat=0x97 intr=0x8 fifo 0x0
esp:            last msg out: NO-OP; last msg in: COMMAND COMPLETE
esp:            DMA csr=0xa4240030
esp:            addr=fc00300a dmacnt=8000 last=fc003008 last_cnt=30
esp:            Cmd dump for Target 1 Lun 0:
esp:            cdblen=6, cdb=[ 0x12 0x0 0x0 0x0 0x30 0x0 ]; Status=0x0
esp:            pkt_state=0x1f pkt_flags=0xb pkt_statistics=0x0
esp:            cmd_flags=0x1422 cmd_timeout=60