From d1cd045982b1e1e4db2c1cc2b2b932f739b78a11 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 12 Nov 2014 22:42:09 -0700 Subject: x86: Emit post codes in startup code for Chromebooks 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 Reviewed-by: Bin Meng --- board/google/chromebook_link/Kconfig | 4 ++++ board/google/common/early_init.S | 21 ++++++++++++++++++++- 2 files changed, 24 insertions(+), 1 deletion(-) (limited to 'board/google') 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..7017185 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 1f + + 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) +1: +#endif jmp early_board_init_ret -- cgit v1.1