RISCOS on Pyra?


Raik

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Do you know if you actually need a hard disc or sd card in it to load RISC OS? I'd kind of assume the entirety of RISC OS is in the flash chip so that it behaves equivalently to the old masked roms that it fitted on old acorn stuff. Point the PC at address 0 and hit go, and the whole thing comes up from there, no fancy bootloaders required.
Titanium: In flash is the bootloader and the ROM. The ROM you can change/update with a FlashSPI or softload if the OS is running.
A harddisc or a sd card you need only for the "harddisc stuff". You can open a rudimentary desktop without a external storage device but but does that make sense? Maybe for debugging.
For configure etc. you need a filcore device (same like Risc PC).
OMAP5 EVM or IGEPv5: Bootloader and ROM are placed on the SD card....
 

levi

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Ah, okay, sounds like it is all in flash (apart from the !Boot folder stuff I guess), but they don't just start running at address zero, and these days have a bootloader which loads an OS from a filesystem. I guess this is because the main users of RISC OS these days are Raspberry Pi users who load the OS from a file on SD after some on-board flash has booted the system, so the code these days is more set up for that kind of launch than the old vector at address 0; now go approach. I guess these days with faster CPUs and faster flash that's going to be comparable to the old way of talking to a physical ROM over a slow system bus (in the RPC line at least; dunno what Castle did for the Iyonix), even with the overheads of navigating a block file system, although I would still assume you want to cache some of the modules (kernel, sprite and sound maybe) in RAM so that you don't have to go to SD every time someone calls an OS_FILE SWI.
 

Raik

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I would still assume you want to cache some of the modules (kernel, sprite and sound maybe) in RAM...
I think (more I'm sure) that the ROM is loaded complete to the RAM ... since Iyonix times.
 

levi

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That's entirely plausible. Back in the days up to the ARM 3 that'd have been prohibitive; the 512kB ROMs in my Archimedes would have taken up half of the system RAM, and when I plugged in 2MB RISC OS 3.10 ROMs in it'd have had a heart attack. On my RISC PC it wouldn't have been so bad, given mine ended up with IIRC 46MB of RAM, and I suspect RISC OS 3.5 was about the same size as 3.1, given they shifted the ROM apps out of the ROM then. According to the good old csa faq, both the Iyonix and the A9 home came with 128MB of plain RAM, so handing a few over to a copy of the OS wouldn't be too bad for them. And of course these days we've gone on to counting out ram not in kB or MB but in GB so unless you're really concerned about the OS being modified while running there shouldn't be any appreciable downside.
 

Raik

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RISC OS 3.7 and 4.39 has 4MB, RISC OS 5.xx 5MB unsqueezed ROMs. So it is not relevant. Have 240MB free on my Classic Pandora after the desktop ist working. Is my standard config. AppDock, Fat32FS and other additional stuff is loaded.
Update and try new ROMs are easier...
My Risc PC has 4.39 "hard" ROMs but softload is possible, not sure what my a9home do. I never look at and I never changed the ROM. Is workink like he should, so I never touch ;)
Titanium is a commercial port.
Back to the Pyra. With the infos I have, the free OMAP5 port should work more or less. As ED wrote, we are using the same development boards. Keep my fingers crossed and wait impatient ;)
 

Raik

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No WiFi, yes :( But "mobile" should be possible. HNS tells me that access via UART is possible if bluetooth not activ. At this time no bluetooth driver are known for RISC OS ;) :(
 
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