Hi Simon,
On Tue, Nov 11, 2014 at 9:00 AM, Simon Glass <s...@chromium.org> wrote:
> On x86 it is common to use 'post codes' which are 8-bit hex values emitted
> from the code and visible to the user. Traditionally two 7-segment displays
> were made available on the motherboard to show the last post code that was
> emitted. This allows diagnosis of a boot problem since it is possible to
> see where the code got to before it died.
>
> On modern hardware these codes are not normally visible. On Chromebooks
> they are displayed by the Embedded Controller (EC), so it is useful to emit
> them. We must enable this feature for the EC to see the codes, so add an
> option for this.
>
> Signed-off-by: Simon Glass <s...@chromium.org>
> ---
>
> Changes in v2:
> - Move early init code into early_board_init
>
> arch/x86/cpu/coreboot/coreboot.c | 3 ++-
> arch/x86/cpu/start.S | 4 ++++
> arch/x86/include/asm/post.h | 32 ++++++++++++++++++++++++++++++++
> board/google/chromebook_link/Kconfig | 4 ++++
> board/google/common/early_init.S | 21 ++++++++++++++++++++-
> 5 files changed, 62 insertions(+), 2 deletions(-)
> create mode 100644 arch/x86/include/asm/post.h
>
> diff --git a/arch/x86/cpu/coreboot/coreboot.c
> b/arch/x86/cpu/coreboot/coreboot.c
> index 874b59d..d9662d9 100644
> --- a/arch/x86/cpu/coreboot/coreboot.c
> +++ b/arch/x86/cpu/coreboot/coreboot.c
> @@ -15,6 +15,7 @@
> #include <asm/cache.h>
> #include <asm/cpu.h>
> #include <asm/io.h>
> +#include <asm/post.h>
> #include <asm/arch-coreboot/tables.h>
> #include <asm/arch-coreboot/sysinfo.h>
> #include <asm/arch/timestamp.h>
> @@ -70,7 +71,7 @@ void show_boot_progress(int val)
> gd->arch.tsc_prev = now;
> }
> #endif
> - outb(val, 0x80);
> + outb(val, POST_PORT);
> }
>
> int last_stage_init(void)
> diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S
> index b18f320..1b738f9 100644
> --- a/arch/x86/cpu/start.S
> +++ b/arch/x86/cpu/start.S
> @@ -13,6 +13,7 @@
> #include <config.h>
> #include <version.h>
> #include <asm/global_data.h>
> +#include <asm/post.h>
> #include <asm/processor.h>
> #include <asm/processor-flags.h>
> #include <generated/generic-asm-offsets.h>
> @@ -67,6 +68,7 @@ _start:
> jmp early_board_init
> .globl early_board_init_ret
> early_board_init_ret:
> + post_code(POST_START)
>
> /* Initialise Cache-As-RAM */
> jmp car_init
> @@ -96,6 +98,7 @@ car_init_ret:
>
> /* Align global data to 16-byte boundary */
> andl $0xfffffff0, %esp
> + post_code(POST_START_STACK)
>
> /* Zero the global data since it won't happen later */
> xorl %eax, %eax
> @@ -131,6 +134,7 @@ car_init_ret:
> call setup_gdt
>
> /* Set parameter to board_init_f() to boot flags */
> + post_code(POST_START_DONE)
> xorl %eax, %eax
>
> /* Enter, U-boot! */
> diff --git a/arch/x86/include/asm/post.h b/arch/x86/include/asm/post.h
> new file mode 100644
> index 0000000..3371185
> --- /dev/null
> +++ b/arch/x86/include/asm/post.h
> @@ -0,0 +1,32 @@
> +/*
> + * Copyright (c) 2014 Google, Inc
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#ifndef _post_h
> +#define _post_h
> +
> +/* port to use for post codes */
> +#define POST_PORT 0x80
> +
> +/* post codes which represent various stages of init */
> +#define POST_START 0x1e
> +#define POST_CAR_START 0x1f
> +
> +#define POST_START_STACK 0x29
> +#define POST_START_DONE 0x2a
> +
> +/* Output a post code using al - value must be 0 to 0xff */
> +#ifdef __ASSEMBLY__
> +#define post_code(value) \
> + movb $value, %al; \
> + outb %al, $POST_PORT
> +#else
> +static inline void post_code(int code)
> +{
> + outb(code, POST_PORT);
> +}
> +#endif
> +
> +#endif
> diff --git a/board/google/chromebook_link/Kconfig
> b/board/google/chromebook_link/Kconfig
> index 975d557..9c715ba 100644
> --- a/board/google/chromebook_link/Kconfig
> +++ b/board/google/chromebook_link/Kconfig
> @@ -12,4 +12,8 @@ config SYS_SOC
> config SYS_CONFIG_NAME
> default "chromebook_link"
>
> +config EARLY_POST_CROS_EC
> + bool "Enable early post to Chrome OS EC"
> + default y
> +
> endif
> diff --git a/board/google/common/early_init.S
> b/board/google/common/early_init.S
> index cf70ae4..15f2ff2 100644
> --- a/board/google/common/early_init.S
> +++ b/board/google/common/early_init.S
> @@ -6,5 +6,24 @@
>
> .globl early_board_init
> early_board_init:
> - /* No 32-bit board specific initialisation */
> + /* Enable post codes to EC */
> +#ifdef CONFIG_EARLY_POST_CROS_EC
> + mov $0x1b, %ecx
> + rdmsr
> + and $0x100, %eax
> + test %eax, %eax
> + je 2f
1f, maybe nitpicking.
> + mov $0x8000f8f0, %eax
> + mov $0xcf8, %dx
> + out %eax, (%dx)
> + mov $0xfed1c001, %eax
> + mov $0xcfc, %dx
> + out %eax, (%dx)
> + mov $0xfed1f410, %esp
> + mov (%esp), %eax
> + and $0xfffffffb, %eax
> + mov %eax, (%esp)
> +2:
1:
> +#endif
> jmp early_board_init_ret
> --
Regards,
Bin
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
