Linaro QEMU

qemu-maemo: amount of RAM for beagle/beaglexm not configurable

Bug #645304 reported by Peter Maydell
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Linaro QEMU
Won't Fix
Wishlist
Peter Maydell

Bug Description

The new qemu-maemo package 0.0~20100921+871d996-0ubuntu1~linaro1 added support for beaglexm. However in the process it has lost the ability to set the amount of RAM on the command line. Now the -m option is ignored, and you always get 128M of RAM on beagle and 512M on beaglexm.

Two things:
 (1) it would be nice if we could have the RAM size configurable but defaulting to the standard board size, but qemu doesn't seem to permit this (you can't tell at the board level whether the ram was given on the command line or not)
 (2) apparently beagle C1D and newer have 256MB, not 128M. Since we claim via the GPIO ID lines to be a rev C4 we ought to model the C4's memory size.

Revision history for this message
Loïc Minier (lool) wrote :

we could extend emulation to revA, revB, etc. but I'm not sure it's very useful; emulating the latest beagle, the latest beagle xm, and having some control of the emulated memory are probably good enough

Revision history for this message
Peter Maydell (pmaydell) wrote :

Part (2) has been fixed in qemu-maemo upstream by their merging my patch for that:
 http://meego.gitorious.org/qemu-maemo/qemu/commit/c22e129c876edf64d8d9ee3541079a81a5b0e51c

Revision history for this message
Loïc Minier (lool) wrote :

Keeping for part 1)

affects: qemu-maemo → qemu-linaro
Changed in qemu-linaro:
assignee: nobody → Peter Maydell (pmaydell)
importance: Undecided → Wishlist
status: New → Confirmed
Revision history for this message
Peter Maydell (pmaydell) wrote :

A long time ago I wrote:
> (1) it would be nice if we could have the RAM size configurable

but I now think this isn't feasible. Software running on the Beagle assumes it can predict the RAM size. In particular U-Boot SPL (and I think X-Loader before it) detect the board type by probing for various ID registers, NAND manufacturer ID, etc, and assume that they can correctly program the SDRC memory controller with fixed values on that basis; this includes setting fields for "how much RAM do we have?". If the model doesn't actually provide the same amount of RAM as the boot loader is programmed to assume then things go badly wrong. So there's no point in providing a user-settable RAM size parameter even if it was conveniently possible.

So I'm going to close this bug as Won't Fix.

Changed in qemu-linaro:
status: Confirmed → Won't Fix
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