Take this particular thread from a week ago, as an example:viewtopic.php?f=1&t=28166
I'm getting the memory map from GRUB via multiboot_info structure, the information I got is in the attachment.
the 4 columns are: size, addr, length, type. As of in the multiboot spec.
But where is the info about memory range 0xA0000~0xEFFFF? it's missing from the mmap.
Would you expect "memory" in that area?
According to the OSDev Wiki Page: http://wiki.osdev.org/Detecting_Memory_(x86
Treat unlisted regions as Type 2 -- reserved.
Apparently GRUB doesn't do this for you. You'll have to detect these and actively avoid them.
Also, from the same page:
GRUB simply uses INT 15h, EAX=E820 to get the detailed memory map, and does not verify the "sanity" of the map. It also will not sort the entries, retrieve any available ACPI 3.0 extended DWORD (with the "ignore this entry" bit), or clean up the table in any other way.
Another problem is that the "type" field is defined as "1 = usable RAM" and "anything else is unusable". Despite what the multi-boot specification says, lots of people assume that the type field is taken directly from INT 15h, EAX=E820 (and in older versions of GRUB it is). However GRUB2 supports booting from UEFI/EFI (and other sources) and code that assumes the type field is taken directly from INT 15h, EAX=E820 will become broken. This means that (until a new multi-boot specification is released) you shouldn't make assumptions about the type, and can't do things like reclaiming the "ACPI reclaimable" areas or supporting S4/hibernate states (as an OS needs to save/restore areas marked as "ACPI NVS" to do that). Fortunately a new version of the multi-boot specification should be released soon which hopefully fixes this problem (but unfortunately, you won't be able to tell if your OS was started from "GRUB-legacy" or "GRUB2", unless it adopts the new multi-boot header and becomes incompatible with GRUB-legacy).
Now, imagine how this looks to the person asking the original question, and how it looks to newcomers who may have also been searching for this exact question. If the only answer was "What did you expect?", that user will probably stop asking questions on this site altogether, and others searching for the same question will probably never come back.
You guys are free to post whatever you want, short of verbally abusing people for no reason, but if you are going to officially make a statement about the purpose of the forum, as it pertains to helping people find answers to questions, I think that it should include a statement saying that questions should be (politely) answered with the goal of quickly connecting the OP with the answer that they are looking for, and perhaps some additional suggestions about how this information can be found.