My RCA RC3000A digital boombox port of Rockbox started getting unexpected shutdowns at startup after I upgraded it to a newer version of Rockbox. A binary search showed it happened when the audio thread starts, but that made no sense! Simply starting the thread and making it execute a loop which only sleeps was enough to cause shutdowns.
Then I saw that they didn't happen when I loaded via USB boot. It made me suspect that some initialization performed by the Rockbox bootloader caused problems later on when the chip is re-initialized by Rockbox. My first guess was cache, prompted by how ROLO flushes ARM cache but doesn't disable it. Disabling the cache fixed the problem when loading Rockbox via ROLO. It also had to be disabled in another place to fix the bootloader.
The TCC760 uses standard ARM940T cache. I'm not sure if this affects other similar ARM cores or other Telechips SoC families.