Add lua code to check whether ei/di and ext instructions are supported. This
is unclear since xburst is somewhere between mips32r1 and mips32r2. Details
results are below, but in summary: they don't work (ei has no effect, di/ext
cause illegal instruction exceptions)
> ./hwstub_shell -q -b -e 'require("jz/misc"); JZ.misc.enable_sram()' \
-f lua/xburst.lua -e "XBURST.test_ext_inst(0xb32d0000)"
[...]
Selecting soc jz4760b. Redirecting HW to hwstub.soc.jz4760b
data: d7168acf
error: lua/xburst.lua:209: call failed
trapped exception in call
> ./hwstub_shell -q -b -e 'require("jz/misc"); JZ.misc.enable_sram()' \
-f lua/xburst.lua -e "XBURST.test_ei_di_inst(0xb32d0000)"
[...]
Selecting soc jz4760b. Redirecting HW to hwstub.soc.jz4760b
Testing ei
Test SR
Enable interrupts with CP0
SR: 0x1
Disable interrupts with CP0
SR: 0x0
Test ei/di
Enable interrupts with ei
SR: 0x0
Disable interrupts with di
error: lua/xburst.lua:244: call failed
trapped exception in call
Change-Id: I2e162b5dd5e70488bcd8b58f3ca401a3ecab3c4b
fdb98c258f