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How is BIOS ROM available at 0xFFFFFFF0 if the A20 line is disabled by default?

I read about the A20 line http://wiki.osdev.org/A20_Line , which seems to indicate that the A20 line is disabled by default. On a Pentium, if 0xFFFFFFF0 is the address displayed immediately after a hard reset, does this mean that the A20 line is turned on by default?

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From my point of view, the OP related article is a bit misleading and should say that the A20 line is disabled by default from the OS / bootloader point of view. This would enable it by default, and the firmware disable it at boot time.

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Source: https://habr.com/ru/post/1606078/

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