From d0b79c54fc14f1f2db64180a21b84146028c598b Mon Sep 17 00:00:00 2001 From: Jimi Xenidis Date: Mon, 26 Jun 2006 04:56:58 -0400 Subject: [POWERPC] Skip the "copy down" of the kernel if it is already at zero. This patch allows the kernel to recognized that it was loaded at zero and the copy down of the image is unnecessary. This is useful for Simulators and kexec models. On a typical 3.8 MiB vmlinux.strip this saves about 2.3 million instructions. Signed-off-by: Paul Mackerras diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index da09242..f2fab68 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -1664,6 +1664,9 @@ _STATIC(__after_prom_start) /* i.e. where we are running */ /* the source addr */ + cmpdi r4,0 /* In some cases the loader may */ + beq .start_here_multiplatform /* have already put us at zero */ + /* so we can skip the copy. */ LOAD_REG_IMMEDIATE(r5,copy_to_here) /* # bytes of memory to copy */ sub r5,r5,r27 -- cgit v0.10.2