History
In 1997, Phase5, an Amiga hardware manufacturer, launched their range of PowerPC (PPC) accelerators for the Amiga. Because AmigaOS was not yet PowerPC native, as a stopgap measure the PowerUP boards were dual-processor boards, incorporating the PPC and a 68K processor (68LC040, 68040 at 25 MHz or 68060 at 50 MHz). They carried the PowerUP kernel onboard in an EPROM, a similar kernel designed to allow AmigaOS applications to use both PPC and 68k applications through an API library called ppc.library. AmigaOS still required a 68K processor, while the PPC was in effect used as an extremely fast coprocessor that carried out specific instructions.
Unfortunately, this caused significant slowdown when the OS task switches between the 68K and PPC (a context switch), because CPU caches had to be flushed to maintain memory integrity. The more CPU switches occur in an application, the more the slowdown, often so seriously that it was pointless to use the PPC processor at all, being slower than the 68k native binary. The main workaround for this was simply to avoid as many 68k OS calls as possible, or to group them together, but it was difficult and time-consuming for developers to do this.
WarpOS was launched as a controversial alternative to Phase5's PowerUP kernel, but eventually became the most used and nominally the standard PPC kernel on AmigaOS.
Read more about this topic: Warp OS
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