[Seb.26]

the extra 64mb ram in the xbox cannot be used for picture or video display purposes as the graphics card has no access to it. you don't really gain much from it.

arrrghhhh ... :tear:

and in your opinion, is it possible to "free" first 64mb from all possible and put this in second ram part ... finaly use this free mem for display purpose ... like output buffer ...

[KSN]

so after all there is nothing that can be done to xbmc code to benefit the extra mem?

and hey if anyone want to have more ram installed i could do it, but i guess it's not much use for it :lol:

[Butcher]

arrrghhhh ...  :tear:

and in your opinion, is it possible to "free" first 64mb from all possible and put this in second ram part ... finaly use this free mem for display purpose ... like output buffer ...  

that's done automatically already by the xdk memory manager. however you can't really move that much stuff up to the upper 64mb - most of the gui memory is textures, which have to be kept in video card accessable memory.

[Seb.26]

ok ... :tear: ... thanks for info ...

and if user interface is 100% cpu drawed ?
... texture not have to be in first bank
... but maybe not easy to do ... and cpu not enought fast ...

[edit] or i think mplayer can render frame directly in second bank ( 0% cpu more work ) ... is it long to copy a frame from second to first bank ? ... how many % of the time that elapse between 2 vbl ?
does the xbox have a memory block transfer chipset ( like blitter on amiga / atari-ste ) , and if, can operate on second memory bank ?

maybe a lot of work ... for minor % of users ...

[KSN]

so if i understand this correctly the gpu cannont acces the extra mem, because it's originally not supposed to..
but
this needs to be set up somwhere, could it be in the bios itselfe, ore in the kernel.? maybe it's in a eeprom?

i'm 100% sure that this can be changed because the box was originally designed to use 128mb

[Seb.26]

so if i understand this correctly the gpu cannont acces the extra mem, because it's originally not supposed to..
but
this needs to be set up somwhere, could it be in the bios itselfe, ore in the kernel.? maybe it's in a eeprom?

i'm 100% sure that this can be changed because the box was originally designed to use 128mb

or maybe the gpu databus don't go to second ram bank ... and the only thing you can do ( lol ) is cry ... :p

i think it's a hard thing you ask for ... really understand a mother board is not an easy task ... but maybe you're right, and a simple jumper can enable second bank, but imo nobody exept m$ people can answer ...

[KSN]

he he.
yes seb.26 your right no esay task this, might even be impossible but one have to try

i'm not an expert at all but my guess is that the lines from the gpu is not directly to the ram but is assignet memory locations in the ram from bios?

[Seb.26]

maybe ... i don't know ...

... to be continued ...

[Butcher]

lot of questions/points here.

cpu draw - too slow.

blitter chip - no, all memory copies are done via the cpu (usually 4 or 8 bytes at a time).

moving a block from the low bank to the high bank will only occur during an allocation - if you try to allocate low memory and there isn't any it'll move a block of possible (slowly).

nor sure on enabling access. the xbox memory controller is on the gpu so it has hardware access to all 128mb. however the xdk functions to allocate memory for the gpu will not allocate memory from the upper 64mb. it would basically mean rewriting the memory management subsystem entirely to enable it's use. bios flashing won't help at all.

[KSN]

well ok.
this makes sense. am i right to asume that the memory alocation is controlled by the bios?

so if someone had the source code for the original bios it would be possible to rewrite it and compile a new bios file?

[Seb.26]

however the xdk functions to allocate memory for the gpu will not allocate memory from the upper 64mb. it would basically mean rewriting the memory management subsystem entirely to enable it's use.

does a memory block allocated by gnu compiler is usable in m$ xdk ... for exemple, create a very simple library with gnu compiler to only allocate gpu memory ... and use it in m$ xdk ...

nb: this only if gnu compiler allow memory allocation in the upper 64mb ... :nuts:

[Butcher]

the gnu libs do not work on xbox. currently xbmc emulates all gnu library calls via the xdk to obtain proper behaviour from mplayer (including malloc/free). memory allocated for use in gnu code can be from the upper or lower 64mb, however it is not accessable by the gpu directly.

[Kjetil N]

so there is a boundery somwhere making it impossible for the gpu to use the extra mem.

what contolls the gpu memory communication?
does it have its own flash? (like a normal gfx pc card)
ore does the gpu itself hold a flash?

could it be possible to mod the mainboard, do some flashing to make the gpu directly acess more mem?

it can be done one a gfx card and my guess is that the hardware in the xbox is not that different?

it must be possible, not easy at all but possible. if not why is it room for more mem?

[Seb.26]

sorry, when i wrote gnu, i thinkf about openxdk ... because i've read post about last release ... but maybe it's the same, and the problem is the same too ...

in any case, does anybody try to add a frame transfer from upper to lower mem ( copy the whole bytes output by mplyer ) ... to see if it is about 0.5% of a "frame time" ( 0.04s ) or if it's more about 20% ...

because if it's about 1% i thing it's a possible solution to have a process who render ( via mplayer in slave mode ) directly in upper ram and another who take next frame from upper, put it in lower ( via copy ) and display it ...

maybe i'm wrong or what i say have no sense ... so excuse me if ...

[gamepc]

can xbmc use 128mb to play video?

in 64mb xbox
when i play hdtv video , i notice freemem soon to 2mb->1mb->0, when zero the video auto stop.

in 128mb xbox
the freemem soon to 64mb-> 63mb->62mb , then the video stop.

i think , xbmc not use 128mb ram .

can xbmc support 128mb to play video?