[PATCH] x86: AUX_DEVICE_INFO is one byte long, use 'movb'

Bugzilla #6552 says:

"In arch/i386/boot/setup.S, movw is used instead of movb for PS/2 mouse
information, although it is unsigned char. This does not harm, because
the jmp instruction overwritten by movw is used before executing movw,
and never be used again"

I've no idea if this is a real bug or how it gets fixed, so I'm submitting
it for review instead of letting it die of boredom in bugzilla. Aditionally
to i386, I've changed x86-64, which mirrors the same code.

Credits to Yoshinori K. Okuji, who found the problem and suggested a fix.

Signed-off-by: Diego Calleja <diegocg@gmail.com>
Signed-off-by: Andi Kleen <ak@suse.de>

2 files changed, 4 insertions, 4 deletions

diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S
index d2b684cd620a..3aec4538a113 100644
--- a/arch/i386/boot/setup.S
+++ b/arch/i386/boot/setup.S
@@ -494,12 +494,12 @@ no_voyager:
         movw    %cs, %ax                        # aka SETUPSEG
         subw    $DELTA_INITSEG, %ax             # aka INITSEG
         movw    %ax, %ds
-        movw    $0, (0x1ff)                     # default is no pointing device
+        movb    $0, (0x1ff)                     # default is no pointing device
         int     $0x11                           # int 0x11: equipment list
         testb   $0x04, %al                      # check if mouse installed
         jz      no_psmouse
 
-        movw    $0xAA, (0x1ff)                  # device present
+        movb    $0xAA, (0x1ff)                  # device present
 no_psmouse:
 
 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
diff --git a/arch/x86_64/boot/setup.S b/arch/x86_64/boot/setup.S
index a50b631f4d2b..c3bfd223ab49 100644
--- a/arch/x86_64/boot/setup.S
+++ b/arch/x86_64/boot/setup.S
@@ -526,12 +526,12 @@ is_disk1:
         movw    %cs, %ax                        # aka SETUPSEG
         subw    $DELTA_INITSEG, %ax             # aka INITSEG
         movw    %ax, %ds
-        movw    $0, (0x1ff)                     # default is no pointing device
+        movb    $0, (0x1ff)                     # default is no pointing device
         int     $0x11                           # int 0x11: equipment list
         testb   $0x04, %al                      # check if mouse installed
         jz      no_psmouse
 
-        movw    $0xAA, (0x1ff)                  # device present
+        movb    $0xAA, (0x1ff)                  # device present
 no_psmouse:
 
 #include "../../i386/boot/edd.S"