[Hero CDMA Android Development] hexskrew:
Hope you folks don't mind but there have been a handfull of people wanting to know how this works and what it exactly entails, so I have been sending this info to folks in pm, so I figured what the heck, and post it here. It's the same exact info as the main screen just maybe a tad bit simplified for clarity.

No problem man!

In a nutshell:

There are three parts to the partition system:

-making the mtdpartmap.txt (holds settings for what you want the partitions to be)

-the FR-recovery-v1.5.3-CustomMTD_S.zip file (edits recovery to use the mtdpartmap.txt file to 'virtually' change the size of the partitions

-the FR-boot-v1.5.3-CustomMTD_S.zip (which tells the kernel of your rom how to use the space set by the virtual partitions)

Here is the theory: virtually (but not really) resize the partitions that are usually left empty, and giving that space to the partitions that usually could need it. i.e. the data partition.

Example and explanation of the mtdpartmap.txt file:

mtd 180 30 (this is my sizes)

The way it works is like this: the first number is the amount to allocate for the system partition, the second for the cache partition, and the third (or rather whatever is left) is for the data partition. The firerat mod system will automatically recalculate what is left for data to use.

The data partition is the key cause that's technically where apps would be installed (if not using apps2sd). Also instead of using the cache partition for dalvik, it will symlink it to data, therefore relieving any real use over 4mb for the cache partition (btw usually the cache partition is rather big)

The point your really looking to get to is to have 2mb available for the system partition, and then 2mb availible for the cache partition, effectively throwing the rest into the data partition, which is how I have 152mb of space left on my phone (had 162mb at install :P) (the space left IS from the data partition)

To install: make the mtdpartmap.txt file in notepad, select what sizes you want (strongly recommended somewhere around 160 to 180mb for system, and for 2.2w/sense start with 10mb for the cache because you can get errors, or missing apps upon install) inside the file, and save to the memory card.

Boot into recovery and make a nandroid if you wish to use the rom already on the phone. Afterward, wipe everything on the phone itself, and then flash the FR-recovery-v1.5.3-CustomMTD_S.zip file. After that, using adb, type adb reboot recovery to reboot the phone into recovery (even though your already in recovery, because you need to effectively 'reboot' the recovery for the new settings to stick from the FR-recovery file) (or if your using clockwork mod, go to advanced and then select reboot recovery).

After getting back into recovery, wipe again so to ensure there is no random crap left on the phone before you either restore your nandroid (will give errors about cache but don't worry, it will rebuild the cache in the right place), or flash a new rom.

NOW VERY IMPORTANT! After you nandroid back or flash a new rom, you have to make sure the kernel knows how to use the partitions (i.e. patch the kernel so that it knows to change the location of the actual cache to the data partition). To do this, after EVERY flash or nandroid restore, you have to flash the FR-boot-v1.5.3-CustomMTD_S.zip Yes this can be a bit of a pain in the ass cause you have to keep that file handy incase you forget when you flash a new rom :P

**btw, great work firerat!**