[HTC Wildfire S] no.human.being:
HTC the phone, Qualcomm the chip, Google the firmware.

The "secure components" are bootloader + Radio. The bootloader is installing firmware updates and verifying signatures, the Radio is controlling memory protection. There are other "secure components" like the low-level controller firmware by Qualcomm that provides an EFI-like environment and also verifies the integrity of the controller and of itself by cryptographic methods.

The bootloader has been unlocked to prevent the Free Software Foundation from suing the hell out of Android phone manufacturers. The aARM fimware (Android) makes use of GPLed components and it is against the GPL to protect software against modification. I think the current state still violates the license terms, since it requires you to sign up with your vendor and request a token (RSA certificate) before you can unlock the bootloader and it still links proprietary (HBOOT) and free (Android kernel) software to form a "contiguous product", but it's not as bad as it used to be. S-ON protects the firmware components that are not licensed under GPL (Radio, bootloader) from being modified. In this case, the protection is ok, but the use of GPL and proprietary components in a single product is not. You either use all-GPL or all-proprietary software, but mixing is not allowed. After all that's the only kind of "compensation" the FSF gets for their work. As soon as someone makes use of their products, that one has to GPL his derived works as well and as soon as someone makes use of the derived work, the work that was in turn based on that work must be GPLed as well. So over time, the body of GPL-licensed software will grow and grow until one day no other license model can exist anymore and all software is either illegal or GPL-licensed. You call such a license model "viral" as it "spreads like a disease". :D

Yeah, they lock it down for protecting their intellectual property. Look at the OMAP processors from TI. These can be secured like a fortress. Our Snapdragon is actually quite "permissive" compared to this. :D

You cannot "lock it down". The lock prevents you from modifying the controller's firmware, but remember that you don't have to use a phone to communicate with a network or a NFC chip, you can use any embedded processor that has the transceivers and I/O that's neccessary for this. There are development boards for e. g. the OMAP processor line and the chips that are put on these boards ship with open firmware (more specifically UBOOT and an Embedded Linux kernel, which is what we're trying to get to the MSM in the long run after we get the security open) and are very permissively configurated, even though the OMAPs that are shipped for use in "end user products" (instead of "engineering products") are completely locked down. These boards are sold to the public on the free market, so anyone can grab one of these, it's just that they are sold-out for quite some time, as they seem unable to manufacture enough of these boards to meet the demand. Because of this, they are also quite expensive. But their distribution is not regulated in any way. So if you really want to "mess with a network", it's not that you couldn't get the hardware do so. In this sense, locking the phones down does little to protect the network operators or to protect NFC from fraud. It's all just to protect the IP of the controller manufacturers. If you actually want to protect NFC, you have to protect the original data on the "authorized" devices from being stolen and cloned, not the NFC chip from sending out forged data, just like you protect your credit card from being read out by keeping it in your wallet, not protect the magnetic strip of all cards against being overwritten so that some evil guy can't make a "credit card clone" out of them. :-)

It is.