求解英文patch

各位大侠，本人想修改一下2010.12月本的uboot根目录里的Makefile，因为查到有资料说下面这个PATCH可以修复里面的BUG，但是小弟才疏学浅，无法看懂，望各位大侠能解救，帮小弟分析它是如何一步一步进行修改的。谢谢各位大侠了。
[PATCH] arm: get_sp() should always be compiled
<ratbert.chuang <at> gmail.com>
2010-11-01 07:55:27 GMT
From: Po-Yu Chuang <ratbert <at> faraday-tech.com>
get_sp() was incorrectly excluded if none of
  CONFIG_SETUP_MEMORY_TAGS
  CONFIG_CMDLINE_TAG
  CONFIG_INITRD_TAG
  CONFIG_SERIAL_TAG
  CONFIG_REVISION_TAG
were defined.

Signed-off-by: Po-Yu Chuang <ratbert <at> faraday-tech.com>
---
arch/arm/lib/bootm.c |    4 +---
1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index a1649ee..7734953 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -327,12 +327,12 @@ void setup_revision_tag(struct tag **in_params)
}
#endif  /* CONFIG_REVISION_TAG */

-
static void setup_end_tag (bd_t *bd)
{
        params->hdr.tag = ATAG_NONE;
        params->hdr.size = 0;
}
+#endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */

static ulong get_sp(void)
{
@@ -341,5 +341,3 @@ static ulong get_sp(void)
        asm("mov %0, sp" : "=r"(ret) : );
        return ret;
}
-
-#endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */

http://www.linuxso.com/command/patch.html
你要学一下关于patch打补丁的东西:)

:)谢谢楼上的帮助。