6 Jan
2015
6 Jan
'15
10:57 p.m.
On Jan 6, 2015, at 3:33 PM, random832(a)fastmail.us
wrote:
Was it possible to read/write to the instruction space, or execute the
data space?
In split I/D mode (411) magic number. It is imposible to execute in D space or use
regular data access instructions to access i-space. The addresses are in completely
different spaces (i.e, 0 in data is mapped to different memory than 0 in instruction
space). Some access at the kernel level can be done with MFPI and MPFD instructions.
In write protected, non-split more (410 magic), you could read the I space and you could
jump in to D space. You were prohibited to write the i space.
In non protected mode (407 magic) everything was fair game.