starlet corpocessor

Posted by arasium

starlet corpocessor
February 04, 2010 10:15PM

Registered: 14 years ago
Posts: 161

I'm trying to understand the ios code. But i have some problems with coprocessors. For example:

MCR p15, 0, R0,c7,c5

What is the coprocessor 15 and what are c7, c5?

Is there any documentation about that on wiibrew?

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ekeeke

Re: starlet corpocessor
February 05, 2010 10:47AM

Registered: 15 years ago
Posts: 276

I've been researching the same thing some time ago.
coprocessor 15 is used for system configuration.
cr are coprocessor registers.

You can find register descriptions in the official ARM9 documentation (I don't think it's Wii specific, please correct me if I'm wrong), see links on the Starlet Wiki .

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arasium

Re: starlet corpocessor
February 05, 2010 10:52AM

Registered: 14 years ago
Posts: 161

Ok, if the coprocessor aren't wii specifics, i will find what i want. Thank you.

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arasium

Re: starlet corpocessor
February 12, 2010 09:59AM

Registered: 14 years ago
Posts: 161

I've made some research and i've not found anything :(

So, is someone can help me about the asm command?

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ekeeke

Re: starlet corpocessor
February 12, 2010 12:49PM

Registered: 15 years ago
Posts: 276

well, you didn't search very hard: first link in the Starlet wiibrew page ;-)

[infocenter.arm.com]

Quote

Chapter 2
Programmer’s Model
This chapter describes the ARM926EJ-S registers in CP15, the system control
coprocessor, and provides information for programming the microprocessor.

and, further in that chapter:

Quote

Table 2-18 Cache operations c7
Function/operation Data format Instruction
Invalidate ICache and DCache SBZ MCR p15, 0, Rd> c7, c7, 0
Invalidate ICache SBZ MCR p15, 0, Rd, c7, c5, 0
Invalidate ICache single entry (MVA) MVA MCR p15, 0, Rd, c7, c5, 1
Invalidate ICache single entry (Set/Way) Set/Way MCR p15, 0, Rd, c7, c5, 2
Prefetch ICache line (MVA) MVA MCR p15, 0, Rd, c7, c13, 1
Invalidate DCache SBZ MCR p15, 0, Rd, c7, c6, 0
Invalidate DCache single entry (MVA) MVA MCR p15, 0, Rd, c7, c6, 1

Your mysterious instruction apparently invalidates the Instruction Cache.

Edited 2 time(s). Last edit at 02/12/2010 01:00PM by ekeeke.

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arasium

Re: starlet corpocessor
February 12, 2010 02:12PM

Registered: 14 years ago
Posts: 161

Crap, i've anly used google.... I'm so stupid....

Thank you and excuse my stupidity :D