+/*L:170 Prepare to be SHOCKED and AMAZED. And possibly a trifle nauseated.
+ *
+ * We know that CONFIG_PAGE_OFFSET sets what virtual address the kernel expects
+ * to be. We don't know what that option was, but we can figure it out
+ * approximately by looking at the addresses in the code. I chose the common
+ * case of reading a memory location into the %eax register:
+ *
+ * movl <some-address>, %eax
+ *
+ * This gets encoded as five bytes: "0xA1 <4-byte-address>". For example,
+ * "0xA1 0x18 0x60 0x47 0xC0" reads the address 0xC0476018 into %eax.
+ *
+ * In this example can guess that the kernel was compiled with
+ * CONFIG_PAGE_OFFSET set to 0xC0000000 (it's always a round number). If the
+ * kernel were larger than 16MB, we might see 0xC1 addresses show up, but our
+ * kernel isn't that bloated yet.
+ *
+ * Unfortunately, x86 has variable-length instructions, so finding this
+ * particular instruction properly involves writing a disassembler. Instead,
+ * we rely on statistics. We look for "0xA1" and tally the different bytes
+ * which occur 4 bytes later (the "0xC0" in our example above). When one of
+ * those bytes appears three times, we can be reasonably confident that it
+ * forms the start of CONFIG_PAGE_OFFSET.
+ *
+ * This is amazingly reliable. */