path: root/arch/s390/boot/compressed/head.S
diff options
Diffstat (limited to 'arch/s390/boot/compressed/head.S')
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/s390/boot/compressed/head.S b/arch/s390/boot/compressed/head.S
index f86a4eef28a9..28c4f96a2d9c 100644
--- a/arch/s390/boot/compressed/head.S
+++ b/arch/s390/boot/compressed/head.S
@@ -21,16 +21,21 @@ ENTRY(startup_continue)
lg %r15,.Lstack-.LPG1(%r13)
aghi %r15,-160
brasl %r14,decompress_kernel
- # setup registers for memory mover & branch to target
+ # Set up registers for memory mover. We move the decompressed image to
+ # 0x11000, starting at offset 0x11000 in the decompressed image so
+ # that code living at 0x11000 in the image will end up at 0x11000 in
+ # memory.
lgr %r4,%r2
lg %r2,.Loffset-.LPG1(%r13)
la %r4,0(%r2,%r4)
lg %r3,.Lmvsize-.LPG1(%r13)
lgr %r5,%r3
- # move the memory mover someplace safe
+ # Move the memory mover someplace safe so it doesn't overwrite itself.
la %r1,0x200
mvc 0(mover_end-mover,%r1),mover-.LPG1(%r13)
- # decompress image is started at 0x11000
+ # When the memory mover is done we pass control to
+ # arch/s390/kernel/head64.S:startup_continue which lives at 0x11000 in
+ # the decompressed image.
lgr %r6,%r2
br %r1