From 8705acd6ee97cb7806fd802b690bfd98932bddda Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Tue, 29 Apr 2014 15:19:10 +0200 Subject: [PATCH] x86/boot: use 'hlt' inside terminal loops Signed-off-by: Andrew Cooper --- xen/arch/x86/boot/head.S | 8 +++++--- xen/arch/x86/boot/x86_64.S | 3 ++- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S index 0d87b27737..ca0e97da3b 100644 --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -54,11 +54,11 @@ print_err: mov $0xB8000,%edi # VGA framebuffer 1: mov (%esi),%bl test %bl,%bl # Terminate on '\0' sentinel -2: je 2b + je .Lhalt mov $0x3f8+5,%dx # UART Line Status Register -3: in %dx,%al +2: in %dx,%al test $0x20,%al # Test THR Empty flag - je 3b + je 2b mov $0x3f8+0,%dx # UART Transmit Holding Register mov %bl,%al out %al,%dx # Send a character over the serial line @@ -66,6 +66,8 @@ print_err: mov $7,%al stosb # Write an attribute to the VGA framebuffer jmp 1b +.Lhalt: hlt + jmp .Lhalt __start: cld diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S index 9652edba66..22645d6cf6 100644 --- a/xen/arch/x86/boot/x86_64.S +++ b/xen/arch/x86/boot/x86_64.S @@ -73,7 +73,8 @@ ignore_int: call printk testq $0xff8,%rbp jnz 0b -1: jmp 1b +1: hlt + jmp 1b .section .init.rodata, "a", @progbits -- 2.30.2