[PATCH] x86: AUX_DEVICE_INFO is one byte long, use 'movb' (606bd58d) · Commits · 戴 / test

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>

arch/i386/boot/setup.S

+2 −2

Original line number	Diff line number	Diff line
		@@ -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)

arch/x86_64/boot/setup.S

+2 −2

Original line number	Diff line number	Diff line
		@@ -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"

Admin message