forums.ps2dev.org

bms20 · Joined: 31 Jan 2006 Posts: 1

Folks,

Forgive me, I only got my PSP last Friday.

It looks to me like the nand flash is not directly processor readable - requiring the processor to load an address, then copy the data into ram.

I am wondering how the OS gets into memory in the first place? There must be some other bootstrap code that is responsible for this. Such an additional flash could explain both the need to JTAG flash the boards in production and the rumored process of un-bricking a psp through the serial port...

Any thoughts?

By the way, has anyone actually found the real JTAG interface on the motherboard yet?

-Brett

ryoko_no_usagi · Joined: 29 Nov 2005 Posts: 65

There is likely a small on-chip bootrom (probably not flash) that can load and decrypt the IPL from the nand flashrom.

702781 · Joined: 27 Apr 2006 Posts: 1

yup,i suppose there is a boot program onboard.

this boot program must be test firmware when bootup,if you burned a v1.5 firmware into the nand and use it on a v2.5 board,it can not worked.

dot_blank · Joined: 28 Sep 2005 Posts: 498 Location: Brasil

flashing is not all that is needed .
one would need to collect manufacturer chip maker
and then recalculate a new manufacturer code

there are functions in psp that can do this
...i leave to you to find out how :)

also note that flashing done by sony official techs
through serial port ie...headphone remote is pure
rumor ...they do indeed reflash through a serial port
but not through headphone remote
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groepaz · Joined: 01 Sep 2005 Posts: 305

dot_blank · Joined: 28 Sep 2005 Posts: 498 Location: Brasil

indeed ;)
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digihoe · Joined: 14 May 2005 Posts: 108

The mbus behind the battery or what?

Best regards!

Marco_N · Joined: 29 May 2005 Posts: 46

I've heard the rumours about the special battery & memory stick combination as well (these come as a set for a specific firmware and need to be exchanged with Sony for a new set whenever a newer firmware is released, according to this rumour. IIRC, it started on the Brazilian PSP forum on Orkut.).

Here's a relatively recent thread about the battery pack, the hardware involved, and how it communicates with the PSP:
http://forums.ps2dev.org/viewtopic.php?t=3917

I wonder if any progress has been made, for instance a "battery pack emulator".