mips: add dtb loading support

Kexec for MIPS currently does not support loading devicetrees, unless
they are embedded in the kernel elf file.

Add an option to either pass a new dtb file or - if not specified - to
be generated from existing device tree on the device. As new generic
platforms require a dtb to be passed separately this is required for
such platforms and will be ignored by the kernel otherwise.

Generic kexec infrastructure for dtb support is used.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 8 insertions, 0 deletions

diff --git a/kexec/arch/mips/kexec-mips.c b/kexec/arch/mips/kexec-mips.c
index 867e9c3..2605c17 100644
--- a/kexec/arch/mips/kexec-mips.c
+++ b/kexec/arch/mips/kexec-mips.c
@@ -21,6 +21,10 @@
 #include "kexec-mips.h"
 #include <arch/options.h>
 
+/* Currently not used but required by top-level fs2dt code */
+off_t initrd_base = 0;
+off_t initrd_size = 0;
+
 static struct memory_range memory_range[MAX_MEMORY_RANGES];
 
 /* Return a sorted list of memory ranges. */
@@ -77,6 +81,7 @@ void arch_usage(void)
 	printf(
 	"    --command-line=STRING Set the kernel command line to STRING.\n"
 	"    --append=STRING       Set the kernel command line to STRING.\n"
+	"    --dtb=FILE            Use FILE as the device tree blob.\n"
 	);
 }
 
@@ -103,6 +108,9 @@ int arch_process_options(int argc, char **argv)
 		case OPT_APPEND:
 			arch_options.command_line = optarg;
 			break;
+		case OPT_DTB:
+			arch_options.dtb_file = optarg;
+			break;
 		default:
 			break;
 		}