I'm CC'ing the seabios mailing list. On Sun, Jul 08, 2012 at 02:20:20AM -0700, Yeong Uk Jo wrote: > Recently patched SeaBIOS has LOWMEM features that locates part of > EBDA data in E segment area. This feature is useful only with no > memory manager or basic memory manager like MS-DOS's EMM386. With > advanced memory manager(like QEMM, Memory Commander, etc),this > feature interferes to secure contiguous memory block. - SeaBIOS > 1.7.0 dated 2012.4.15 can use segment C900-FBFF as UMB, but recent > version split C900-EDFF,F000-FBFF.
Older versions of SeaBIOS allocate dynamic ram from the end of the 9-segment, not the EBDA. These allocations were not relocatable. Indeed, the reason the 9-segment was used instead of the EBDA is that some low memory allocations are needed for DMA buffers which must not be relocated. Given the choice between using the 9-segment or the e-segment, I think using the e-segment is preferable. It is true that variables in the EBDA were also moved to the e-segment. This was done as a code simplification (once the e-segment was used, there was no need to use the ebda for internal allocations). This doesn't impact fragmentation, because the dynamic memory allocations already fragment the space. > Note that advanced memory managers can relocate EBDA data to appropriate > area.Experienced users can write program to move EBDA data. > > Jo Yeong-uk -Kevin _______________________________________________ SeaBIOS mailing list [email protected] http://www.seabios.org/mailman/listinfo/seabios
