The TiVo Premiere appears to use the same TTL serial interface as the Gen06 platform (TiVo HD). The unit uses 5V TTL logic to communicate via serial, and any adapters that work with the TiVo HD will also work with the Premiere.

Without any modification to the bootpage, here is what factory TiVo Premiere displays upon power-on:
Code:
Shmoo Version=3.5
DDR Freq=0x0000018C
%00000001%
RC1=00000003
WC1=FFFFFFE2
RC2=00000018
WC2=0000002F
RC3=0000000D
WC3=FFFFFFE2
RC4=0000000D
WC4=0000002F
NWC=00000008
RC5=00000003
WC5=00000008
RC6=00000018
WC6=00000008
NRC=0000000D
RW=00000016
WW=0000004E
G=00000000 R=0000000D W=00000008
BL=00000000
RC1=00000000
RC2=00000015
BL=00000001
RC1=00000003
RC2=00000015
BL=00000002
RC1=00000002
RC2=00000019
BL=00000003
RC1=00000003
RC2=00000019
BL=00000004
RC1=00000001
RC2=00000018
BL=00000005
RC1=00000004
RC2=00000019
BL=00000006
RC1=00000002
RC2=00000017
BL=00000007
RC1=00000002
RC2=00000019
TiVo Gen07 release 1.00 (2009-10-20 14:09:37)
Copyright 2009 TiVo Inc. All Rights Reserved.
TSN: REDACTED BREV: 0x1060 MAC: RE:DA:CT:ED
Thumbprint: 356515097AED79CCEC5097DA723F8FE654826A83
Disk: WDC WD3200AVVS-63L2B0 F/W: 01.03A01 S/N: WD-REDACTED
Booting from partition 3... 3800064 bytes
Kernel signed by '... the Porridge bird ...'
Hashing kernel (SHA256)... done
Checking signature... done.
Signed, valid for release
Kernel entry point is 0x802b8000
cfeBootParms ===> root=/dev/sda4
Kernel boot options: root=/dev/sda4 console=ttyS0,115200 boardID=0x106001 HpkImp
Gen07
BOOTEDFROMFLASH, Base=1c000000
Initial CP0 22 value : 0xe30f3406
node [00000000, 10000000: RAM]
node [20000000, 10000000: RAM]
mips_counter_frequency = 202000000 from Calibration, = 202500000 from header(CPU_MHz/2)
Access to the PROM Boot Menu is no longer restricted by a factory password unique to the unit. Sending ^C to down the line during the first few seconds will display the PROM boot menu.
Currently Known Commands:
Code:
boot [-3,-6]
disk
reset
Kernel message logging via serial can be enabled by connecting the disk to PC and using the bootpage.x86 binary to add "dsscon=true console=0,115200" flags to the bootpage parameters.
Since my USB-SATA adapter was located at /dev/sdb, and the TiVo's bootpage was currently set to "root=/dev/sda4" I issued the following command:
Code:
bootpage.x86 -P "root=/dev/sda4 dsscon=true console=0,115200" -C /dev/sdb