Basic question r/e flash rom

bms20 · Post by **bms20** » Tue Jan 31, 2006 7:41 am

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 · Post by **ryoko_no_usagi** » Tue Jan 31, 2006 7:28 pm

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

702781 · Post by **702781** » Thu Apr 27, 2006 7:55 pm

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 · Post by **dot_blank** » Fri Apr 28, 2006 2:48 pm

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

groepaz · Post by **groepaz** » Sat Apr 29, 2006 12:22 am

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

and thats what? no info but yet another rumor?

dot_blank · Post by **dot_blank** » Sat Apr 29, 2006 1:43 am

indeed ;)

digihoe · Post by **digihoe** » Sat Apr 29, 2006 4:21 am

The mbus behind the battery or what?

Best regards!

Marco_N · Post by **Marco_N** » Sat Apr 29, 2006 6:23 am

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".