Linked by Eugenia Loli on Fri 18th Nov 2005 18:53 UTC
Windows So you just bought a brand new WM5 device. The box says it's got 64M of RAM. You go digging through control panels on the device and find one that says it's only got 50M. Is something wrong? Should you be worried about this? The short answers are "No" and "No." This will explain why. UPDATE: On related news, ActiveSync 4.1 was released.
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Good infromation
by aaronb on Sat 19th Nov 2005 10:17 UTC
aaronb
Member since:
2005-07-06

When I buy a product I do like to know what is going on. Also XIP is very intresting technology that I hope PC can use if HDD are replaced with RAM or FLASH chips of sorts.

Reply Score: 1

RE: Good infromation
by on Sat 19th Nov 2005 12:39 in reply to "Good infromation "
Member since:

XIP would only work with memory-mapped I/O. x86 machines use a seperate address space for I/O devices (in general, VRAM is memory mapped for instance), so there is no way that the IP (instruction pointer) in the CPU could point at an I/O device. Maybe some XIP-like kludge could be put together using DMA, but it would still require that at least the part of the code being executed is loaded into main RAM.

Reply Parent Score: 0

RE[2]: Good infromation
by aaronb on Sat 19th Nov 2005 15:36 in reply to "RE: Good infromation "
aaronb Member since:
2005-07-06

Thanks for the reply. I took an Hour of reading before I understood your post <-;

Reply Parent Score: 1

RE[2]: Good infromation
by agentj on Sat 19th Nov 2005 22:16 in reply to "RE: Good infromation "
agentj Member since:
2005-08-19

Why not ? For example most modern graphic cards use memory mapped I/O. You can create virtual memory area, map it to physical device area and it will work - most modern PCI/AGP cards support it.
For example you write address of memory region to SiS900 NIC, so it uses data from there. For example driver reads that data when it sends/receives data.
If you create memory areas e.g. for NVidia card, you can access VGA config registers both through standard in/out and that memory region.
What's the reason that EIP can be in such mmio area.

Edited 2005-11-19 22:18

Reply Parent Score: 1