- * Reserving memory causing GPU hangs on Sandy Bridge integrated
- * graphics devices should be done after we allocated memory under
- * 1M for the real mode trampoline.
+ * Find free memory for the real mode trampoline and place it
+ * there.
+ * If there is not enough free memory under 1M, on EFI-enabled
+ * systems there will be additional attempt to reclaim the memory
+ * for the real mode trampoline at efi_free_boot_services().
+ *
+ * Unconditionally reserve the entire first 1M of RAM because
+ * BIOSes are know to corrupt low memory and several
+ * hundred kilobytes are not worth complex detection what memory gets
+ * clobbered. Moreover, on machines with SandyBridge graphics or in
+ * setups that use crashkernel the entire 1M is reserved anyway.