CODEWITHSUNDEEP
initbios
peter tang
peter tang

Reputation: 31

Could someone tell me where is the code of BIOS loaded and how much memory does it take?

Could someone tell me where is the code of BIOS loaded when the CPU reset ,and how much memory does it take for different CPU architecture?I only know 64KB.

Upvotes: 1

Views: 81

Answers (1)

juhist
juhist

Reputation: 4314

The BIOS is located in read-only memory (ROM). An x86 CPU automatically starts executing instructions at 4GB minus 16 bytes. This address is mapped to the system ROM. For more information about the x86 bootup process, see http://en.wikipedia.org/wiki/BIOS#System_startup

As for how much memory BIOS takes, it depends on many things. It isn't just dependent on the CPU architecture, but it is dependent on the vendor of the system. Different vendors use different BIOSes that may have different sizes. According to Wikipedia, "BIOS versions now exist with sizes up to 16 megabytes" so perhaps that answers your question about the size of BIOS.

Upvotes: 1

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