can't get Raspbian to see 512 MB RAM

[gertjanol]

I've googled and experimented a lot, but for some reason my Pi (model B, from one of the earliest generally available batches) is stuck with only 256 MB RAM. I've updated the firmware to the latest version, using rpi-update (http://hubcitylabs.org/unlocking-your-n ... of-memory/).

Whatever value I set gpu_mem in /boot/config.txt to is subtracted from 256. gpu_mem=16 leaves the OS 240MB:

$ grep -i memtotal /proc/meminfo
MemTotal: 237648 kB

I don't understand where the remaining 256 MB went. Can anybody help me?

[rurwin]

If you have an early Model B, then it only has 256MB of RAM.
"cat /proc/cpuinfo" will tell you the board revision numbers, and this is what they mean

There are three manufacturers of the boards, and they have unique board revs:

'0002' => 'Model B Revision 1.0',
'0003' => 'Model B Revision 1.0 + Fuses mod and D14 removed',
'0004' => 'Model B Revision 2.0 256MB', (Sony)
'0005' => 'Model B Revision 2.0 256MB', (Qisda)
'0006' => 'Model B Revision 2.0 256MB', (Egoman)
'0007' => 'Model A Revision 2.0 256MB', (Egoman)
'0008' => 'Model A Revision 2.0 256MB', (Sony)
'0009' => 'Model A Revision 2.0 256MB', (Qisda)
'000d' => 'Model B Revision 2.0 512MB', (Egoman)
'000e' => 'Model B Revision 2.0 512MB', (Sony)
'000f' => 'Model B Revision 2.0 512MB', (Qisda)

[gertjanol]

Never mind, already found out that my board is a Model B, Rev 1, which has only 256 MB memory.

Sources
[*] http://en.wikipedia.org/wiki/Raspberry_ ... ifications
[*] http://www.raspberrypi.org/archives/1929