Remember the MSM chipset is an all in one app processor. It has baseband, bluetooth, app cpu, wifi baseband etc all built in. (Of course the analogue basebands are external)
The internal memory of the 7200A is used to map various buffers that all these things use. Memory is then attached on an external bus to expand this memory. However the MMU cannot map certain things to this external bus. Its a limitation by design.
When I say framebuffer I am not talking about the buffer exposed to linux but internal buffers used for things like 3d acceleration. For example your 256mb ATI graphics card on your PC doesnt have a 256mb frame buffer
It is highly unlikely that there are 32mb and 64mb revisions out there. They will all either be 32mb or 64mb. I just had a look at a firmware image and amss section is 20mb, but that is most likely compressed.
Its possible they are using the 32mb die, but in my opinion very unlikely.
Remember because of the nature of these integrated APP processors ALL memory is shared by the peripherals. Its not dynamic but staticly allocated by the MMU.
Quote:
Originally Posted by Russ Dill
It seems very hackish to not tell kernel about memory reserved for the radio, but I can understand the motivation. But as far as other buffers, the kernel would definitely need to know about them since it would have to read/write to them. A frame buffer (or other buffers) isn't very useful if it can't be written to. A 320x480 screen at 32bits per pixel needs to be backed by a mere 600k.
If some Galaxy's have 192MB total and some have 160MB total, I'd certainly like to know about it. Mine says "CPU: ARMv6-compatible processor [4117b362] revision 2 (ARMv6TEJ), cr=00c5387f"
btw, news of the moment, i7500 unlocked on newegg, 589 w/free shipping (newegg claims 128MB ram incidentally)
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