x86, bios: Make the x86 early memory reservation a kernel option

Add a kernel command-line option so the x86 early memory reservation
size can be adjusted at runtime instead of only at compile time.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <tip-d0cd7425fab774a480cce17c2f649984312d0b55@git.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 2c85c0692b01..41ce93e71ded 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2150,6 +2150,11 @@ and is between 256 and 4096 characters. It is defined in the file
                         Reserves a hole at the top of the kernel virtual
                         address space.
 
+        reservelow=     [X86]
+                        Format: nn[K]
+                        Set the amount of memory to reserve for BIOS at
+                        the bottom of the address space.
+
         reset_devices   [KNL] Force drivers to reset the underlying device
                         during initialization.