x86: Change condition for using CAR

At present we assume that CAR (Cache-as-RAM) is used if HOBs (Hand-off
blocks) are not, since HOBs typically indicate that an FSP is in use, and
FSPs handle the CAR init.

However this is a bit indirect, and for FSP2 machines which use their own
CAR implementation (such as apollolake) but use the FSP for other
functions, the logic is wrong.

To fix this, add a dedicated Kconfig option to indicate when CAR is used.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: fix a typo in the commit message]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 314f8de..47bf28c 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -364,6 +364,14 @@ config HAVE_FSP
          Note: Without this binary U-Boot will not be able to set up its
          SDRAM so will not boot.
 
+config USE_CAR
+       bool "Use Cache-As-RAM (CAR) to get temporary RAM at start-up"
+       default y if !HAVE_FSP
+       help
+         Select this option if your board uses CAR init code, typically in a
+         car.S file, to get some initial memory for code execution. This is
+         common with Intel CPUs which don't use FSP.
+
 choice
        prompt "FSP version"
        depends on HAVE_FSP

diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S
index 3c9bdf2..9b76394 100644 (file)
--- a/arch/x86/cpu/start.S
+++ b/arch/x86/cpu/start.S
@@ -90,7 +90,7 @@ early_board_init_ret:
        jmp     car_init
 .globl car_init_ret
 car_init_ret:
-#ifndef CONFIG_USE_HOB
+#ifdef CONFIG_USE_CAR
        /*
         * We now have CONFIG_SYS_CAR_SIZE bytes of Cache-As-RAM (or SRAM,
         * or fully initialised SDRAM - we really don't care which)
@@ -130,7 +130,7 @@ car_init_ret:
 
        /* Get address of global_data */
        mov     %fs:0, %edx
-#ifdef CONFIG_USE_HOB
+#if defined(CONFIG_USE_HOB) && !defined(CONFIG_USE_CAR)
        /* Store the HOB list if we have one */
        test    %esi, %esi
        jz      skip_hob

diff --git a/configs/slimbootloader_defconfig b/configs/slimbootloader_defconfig
index f9fecff..3cbb83c 100644 (file)
--- a/configs/slimbootloader_defconfig
+++ b/configs/slimbootloader_defconfig
@@ -18,3 +18,4 @@ CONFIG_REGMAP=y
 CONFIG_SYSCON=y
 # CONFIG_PCI_PNP is not set
 CONFIG_CONSOLE_SCROLL_LINES=5
+# CONFIG_USE_CAR is not set