How bytes move from spinning platters through kernel buffers into your program's address space. Every post shows real offsets, real hex dumps, real register values.
Every spinning platter and every SSD cell exposes the same interface to the silicon: read slot N, write slot N. Each slot is 512 bytes. That's the entire contract.
At byte offset 1024 from the start of the partition sits a 1024-byte record. It holds total block count, block size exponent, blocks-per-group, and free counts.
Split the path into ["home", "r", "file.txt"]. Start at metadata-record #2 (the root). Walk each name-to-number table. Each step costs one disk read minimum.
When a corrupted stack pointer is dereferenced, the OS acts completely differently depending on the virtual address. A non-canonical address triggers a GPF, bypassing the Page Fault handler entirely.
Locating dynamic inode blocks on disk. Comparing division/modulo calculations in Unix V6 simulator against direct bitwise shifts and AND masks inside the 6.8.0 Linux kernel's sysv_raw_inode.