move GDT under VCPI above 1MB

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Index > OS Construction > move GDT under VCPI above 1MB

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CandyMan

Joined: 04 Sep 2009
Posts: 380
Location: film "CandyMan" directed through Bernard Rose OR Candy Shop

CandyMan 01 May 2016, 18:13

Whether it is possible to copy GDT above the first megabyte in order can switch from the protected mode to the real mode and on the contrary under VCPI?. If this way as it to do it? In raw/xms mode there is no problem.

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smaller is better

01 May 2016, 18:13

zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 01 May 2016, 21:05

In real mode, addresses in range from 0xFFFF:0x0010 to 0xFFFF:0xFFFF address memory above 1MB if A20 line is enabled. Another option is to enter 'unreal' mode and copy above 1MB using 32-bit addressing

01 May 2016, 21:05

CandyMan

Joined: 04 Sep 2009
Posts: 380
Location: film "CandyMan" directed through Bernard Rose OR Candy Shop

CandyMan 02 May 2016, 11:18

I am thanking for help, with it I already advised myself

_________________
smaller is better

02 May 2016, 11:18

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