FDOS/kernel

When allocating HMA the requested size is not rounded up to paragraph

andrewbird opened this issue · 6 comments

andrewbird commented

When using int2f/0x4a02 to get an HMA block the requested size is not rounded up with respect to paragraph, as it is on MS-DOS 6.22/7.0/7.1. This was recently fixed in FDPP dosemu2/fdpp@e7fe81d
See https://github.com/dosemu2/dosemu2/blob/7454efb873977214cd8605380954a4cc86a53441/test/func_memory_hma.py#L61 for an example test, where the requested size is 35 bytes, and the expectation is 48 bytes.

ecm-pushbx commented

This patch as is will overflow for bx > 0FFF0h.

andrewbird commented

Well spotted.

PerditionC commented

updating the hma allocation functions are on my todo list along making sure that the kernel handles multiple umb providers. I am reworking some initialization code, which I plan to include memory management as part of, along with the gpt support I'm working on

  • 👍1
andrewbird commented

updating the hma allocation functions are on my todo list

Will you support the Win9x HMA layout too, see http://www.ctyme.com/intr/rb-4818.htm?

PerditionC commented

yes

andrewbird commented

Cool, then that means the mcbs command in dosdebug can display it nicely.