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kandeshvari / phantomuserland

Automatically exported from code.google.com/p/phantomuserland
GNU Lesser General Public License v3.0
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Bogus physram #48

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
boot/dumpf: [0x0049B21F5 - 0x0080F0000[ (  55 M) - hi RAM

In fact 0x008000000 to 0x0080F0000 seems to be non-working RAM.

Why?

Original issue reported on code.google.com by dmitry.zavalishin@gmail.com on 14 Jun 2010 at 11:29

GoogleCodeExporter commented 9 years ago 
Quote from multiboot specification:
"The value returned for upper memory is maximally the address of the first 
upper memory hole minus 1 megabyte. It is not guaranteed to be this value"

Since upper memory starts at 1 megabyte, the value is essentially the upper 
memory size. So, there's extra START_UPPER, because SET_MEM expects size as the 
second parameter:
SET_MEM(START_UPPER, START_UPPER + bootParameters.mem_upper * 1024, 
MEM_MAP_HI_RAM );

Fixed at r438.

Original comment by jcmvb...@gmail.com on 25 Jun 2010 at 4:57