tag
5 posts
Follow the E820 continuation protocol, validate firmware descriptors, and distinguish physical address ranges from memory DOS can allocate.
Gate CPUID safely, enumerate only supported leaves, and translate processor feature bits into conservative DOS execution requirements.
Distinguish processor exceptions from DOS interrupts, understand the original 8086 vector contract, and build handlers that preserve state and return safely.
Explore the 8086 architecture behind x86: 20-bit physical addressing, overlapping 64 KiB segments, the EU/BIU prefetch queue, and the 8088 bus trade-off.
Understand legacy BIOS disk calls, probe Enhanced Disk Drive support, distinguish BIOS drive IDs from DOS letters, and avoid filesystem corruption.