new to Eris but IV been rooting for a wwhile on the lg ally but we didn't have a boot loader what iis it and what are the options to have amd whats the bbest?
It is highly likely that your Ally had/has
something which acts as a bootloader, although you may not have had more than one choice of versions available to you.
Bootloaders are sometimes called "IPL" (Initial Program Loader) or "SPL" (Secondary Program Loader) - they are usually real-mode code responsible for preparing the device to boot a Linux kernel image. In principle, they could be extremely simple bits of code, or they could be quite sophisticated; but they are almost always proprietary, as they are highly specific to an individual device.
In the standard Android "usage model", there are two different boots available: the normal boot, and the recovery boot. Optionally, there is another mode where the phone listens on a hardware port for a specific, simple, (and extensible) Android protocol called "fastboot", and this can be used by the device manufacturer to create whatever they want for maintenance, diagnostics, testing, etc.
At a minimum, though, probably a primitive bootloader does things like read the state of buttons which are pressed on the phone at start-up, to allow the phone's user to select the normal boot or the recovery boot.
HTC's bootloader on the Eris is more sophisticated than this, and has 3 major modes of operation: HBOOT, FASTBOOT, and RUU... in addition to it's "normal" use where it is only alive for a fraction of a second before it passes control to the regular OS during booting.
I won't tell you to pick a certain version, but there have been 4 different Eris bootloaders released into the wild:
1.46.0000 S-ON
1.47.0000 S-ON
1.49.0000 S-ON
1.49.2000 S-OFF
The S-OFF version was leaked by someone who had access to HTC engineering samples - the "S-OFF" designation means that all the normal "security" checks that the bootloader performs for a production phone (S-ON) are disabled. This means that it is more capable, and also more dangerous - you could easily brick your phone using it without understanding what you are doing.
My advice to you is you search here and on XDA for the terms "HBOOT", "FASTBOOT", and "RUU", and then decide what you want to do; in the meantime, changing your bootloader (
the single most dangerous flashing operation you can perform on your Eris) isn't necessary for trying out new ROMs.
eu1