Paul som driver och står bakom entusiastsajten MoDaCo.com har nu presenterat en guide för hur man går tillväga för att få root-åtkomst på HTC Desire.

Proceduren är tyvärr rätt knepig och långt från så enkel som på Googles Nexus One, där ett enstaka kommando (fastboot oem unlock) låser upp telefonen och tillåter flashning av osignerade ROM-filer.

Root-åtkomsten är också begränsad så tillvida att man inte får skrivrättigheter till systempartitionen med operativsystemet igång, det går ej heller att flasha in en ny recovery-konsol som går att starta genom att tex hålla inne bakåtknappen när man startar telefonen, som brukligt på så många andra lurar.

HTC har med Desire alltså skruvat upp säkerheten rejält och vi kan med all säkerhet vänta oss att det blir än tuffare framöver, något den nyare bootloadern (0.80) som följer med den O2-brandade (Tysk mobiltelefonoperatör) versionen av Desire vittnar om – här har Paul ännu inte lyckats få root-åtkomst. Siktet tycks vara inställt på att helt låsa ute de som vill köra modifierade versioner av Android på HTC-brandade telefoner.

I textstycket nedan redogör Paul för vad som är nytt på säkerhetsfronten och hur han i grova drag lyckats åstadkomma root-åtkomst på telefonen:

[Guiden hittar ni här]

Desire rooting protection

Back in the early days of Android, rooting was easy. You had several options – you could flash stuff via the bootloader, you could flash an engineering bootloader, you could use kernel exploits – there were many ways of getting the low level access to your device that – in fairness – I think we as paying customers are entitled to. As time has progressed however, the manufacturers have made things harder and harder. The Desire is not a straightforward phone to root, for many reasons, including…

• a ’perfected bootloader’ that doesn’t allow flashing or booting of any images (even HTC signed ones)
• a RUU flash process that does not allow downgrading of the bootloader to earlier versions
• a kernel (that as yet does not have publicly available source) that as yet has no known exploits
• a new protection method previously seen on the HTC Tattoo that protects key partitions from having write access. Even with SU access, it is not possible to write to the boot, recovery or system partitions.

In reality, the options for rooting a device this secure are limited. Even if a kernel exploit were found, the key partitions would still be unwritable, rendering su access useless. This was circumvented on the Tattoo very cleverly, using a specific memory address from a confidential Qualcomm datasheet, however this information is not yet available for the Snapdragon chipset used in the Desire (and indeed may never enter the public domain).

And so the root process becomes a process of methodically probing every possible point of exposure on the device, looking for the slightest chink in the armour. I found one and we’re putting it to good use! The downside is that it’s not as easy or as pretty as rooting a device that is actually DESIGNED to be accessible at the lowest level, such as the Nexus One.

Shame on you HTC for going to such unnecessary lengths (but that’s another story for another day).

-Paul @ MoDaCo.com

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