Writing 0xcb to I/O port 0xb2 (Advanced Power Management Control) causes U-Boot to hang on QEMU q35 target. We introduce a config option in the device tree "u-boot,no-apm-finalize" under /config node if we don't want to do that.

Signed-off-by: Bin Meng bmeng.cn@gmail.com

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Changes in v2: - Use a config option in the device tree instead of deleting the codes

arch/x86/cpu/coreboot/coreboot.c | 12 +++++++++--- arch/x86/dts/qemu-x86_q35.dts | 1 + 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/x86/cpu/coreboot/coreboot.c b/arch/x86/cpu/coreboot/coreboot.c index c3dfd28..c4cac04 100644 --- a/arch/x86/cpu/coreboot/coreboot.c +++ b/arch/x86/cpu/coreboot/coreboot.c @@ -7,6 +7,7 @@ */

#include <common.h> +#include <fdtdec.h> #include <netdev.h> #include <asm/io.h> #include <asm/msr.h> @@ -74,9 +75,14 @@ void board_final_cleanup(void) mtrr_close(&state); }

- /* Issue SMI to Coreboot to lock down ME and registers */ - printf("Finalizing Coreboot\n"); - outb(0xcb, 0xb2); + if (!fdtdec_get_config_bool(gd->fdt_blob, "u-boot,no-apm-finalize")) { + /* + * Issue SMI to coreboot to lock down ME and registers + * when allowed via device tree + */ + printf("Finalizing coreboot\n"); + outb(0xcb, 0xb2); + } }

int misc_init_r(void) diff --git a/arch/x86/dts/qemu-x86_q35.dts b/arch/x86/dts/qemu-x86_q35.dts index 6c89283..02a483c 100644 --- a/arch/x86/dts/qemu-x86_q35.dts +++ b/arch/x86/dts/qemu-x86_q35.dts @@ -15,6 +15,7 @@

config { silent_console = <0>; + u-boot,no-apm-finalize; };

chosen {