I tried disassembling the HDPro installer before - but I remember getting stuck because I can't decompress/de-scramble it.
Yes, this ELF is scrambled and/or compressed in some funny way (Not with PS2-packer).
I can't proceed unless it's decompressed and/or de-scrambled.
EDIT: My bad. I kept forgetting that there was an ancient PS2 executable compressor called "sjcrunch" (So I used sjuncrunch to decompress it).
Unmodified SCPH-77006 with SM 3.6
SCPH-39006 with M-chip modchip, SCPH-10281 NA and refurb Seagate 80GB HDD
SCPH-10000 v1.00 with SCPH-10190 PCMCIA NA and SCPH-20400 HDD unit