+ /*
+ * Run through the initial boot mappings, log the established
+ * ones, and blow away anything that falls outside of the valid
+ * PPN range. Specifically, we only care about existing mappings
+ * that impact the cached/uncached sections.
+ *
+ * Note that touching these can be a bit of a minefield; the boot
+ * loader can establish multi-page mappings with the same caching
+ * attributes, so we need to ensure that we aren't modifying a
+ * mapping that we're presently executing from, or may execute
+ * from in the case of straddling page boundaries.
+ *
+ * In the future we will have to tidy up after the boot loader by
+ * jumping between the cached and uncached mappings and tearing
+ * down alternating mappings while executing from the other.
+ */