[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v7] arm: Add Kconfig entry to select CONFIG_DTB_FILE


  • To: Michal Orzel <Michal.Orzel@xxxxxxx>
  • From: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>
  • Date: Mon, 15 Mar 2021 10:29:15 +0000
  • Accept-language: en-GB, en-US
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=arm.com; dmarc=pass action=none header.from=arm.com; dkim=pass header.d=arm.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=pSKQAci77+VJmJ0vscZTCxSI6oueURxbYe5hjUdP5TI=; b=KWFfbPHSvfqKQjUEtO2A5NEtaxF/941eveGpbz/REFGLYwyQv6tYeeEK9i9cP0LmelfUDn62FLBvXEFJBf9XxUVKsswfxLl6bkNF5rHro5mDhB9/ISUDd4d2jLRJQj0OaacquaO8j9SjFXXOw+xKKRFPkMhb2za3XRM99Oe0u4ahsrw0soTlmek5btFhV7nCHGrF62ZQQVFVfu98XMcVEMKTaBh7bWyQ+5jPe0cAGaVJoCZTjIxZk80KGd3/8bCyE1QI59zFFmGUGpzhc12k/IJt2RCbNi7JeOW8nWzs5pkZjo4D2IktNb91AS17h5UGSvTw6Kejq6HSsnj45/EzZg==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=gEIYJdc0yyi5RXnQOrQNUs6YHStEwHKlUP6grD2AZWAABBCHLTaD/p6nCVMiZ0BkyxFrI2MOW+RJQ6KYZH2k/pCIu/WnWBXYvDI4byiSc9LgD1fgX+kjGoCYkf23U1+Kl7UxEkbVyYIaOXWQMpClhkRJMaj64dSZfIEEcrNRgy8+UYIpCZV68b0HUKWFe9HWcLHw7BldmvgaOtMs4iX7U6gCNRxdj/0jfiIgD2k2BiViWiDUFawslVi0kcQaixpf75keukQJ+77AdkK4ZXXVuTJY7a/KAFlfep3hdpkEdwGHnF5El+KMEg5nlVHlB32OOZae1NfmHLSMpKVNv558ww==
  • Authentication-results-original: arm.com; dkim=none (message not signed) header.d=none;arm.com; dmarc=none action=none header.from=arm.com;
  • Cc: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, George Dunlap <george.dunlap@xxxxxxxxxx>, Ian Jackson <iwj@xxxxxxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>, Wei Liu <wl@xxxxxxx>
  • Delivery-date: Mon, 15 Mar 2021 10:30:27 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
  • Nodisclaimer: true
  • Original-authentication-results: arm.com; dkim=none (message not signed) header.d=none;arm.com; dmarc=none action=none header.from=arm.com;
  • Thread-index: AQHXGXzxZpQ/TGqhSkqtfY2YUu6quKqE2RuA
  • Thread-topic: [PATCH v7] arm: Add Kconfig entry to select CONFIG_DTB_FILE

Hi Michal,

> On 15 Mar 2021, at 09:23, Michal Orzel <Michal.Orzel@xxxxxxx> wrote:
> 
> Currently in order to link existing DTB into Xen image
> we need to either specify option CONFIG_DTB_FILE on the
> command line or manually add it into .config.
> Add Kconfig entry: CONFIG_DTB_FILE
> to be able to provide the path to DTB we want to embed
> into Xen image. If no path provided - the dtb will not
> be embedded.
> 
> Remove the line: AFLAGS-y += -DCONFIG_DTB_FILE=\"$(CONFIG_DTB_FILE)\"
> as it is not needed since Kconfig will define it in a header
> with all the other config options.
> 
> Make a change in the linker script from:
> _sdtb = .;
> to:
> PROVIDE(_sdtb = .);
> to avoid creation of _sdtb if there is no reference to it.
> 
> Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>

The use of ifnes and PROVIDE is very clever :-)

Cheers
Bertrand


> ---
> xen/arch/arm/Makefile     |  5 ++---
> xen/arch/arm/arm32/head.S |  4 ++--
> xen/arch/arm/arm64/head.S |  4 ++--
> xen/arch/arm/xen.lds.S    |  4 +---
> xen/common/Kconfig        | 10 ++++++++++
> 5 files changed, 17 insertions(+), 10 deletions(-)
> 
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index 16e6523e2c..46e6a95fec 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -68,9 +68,8 @@ extra-y += $(TARGET_SUBARCH)/head.o
> 
> #obj-bin-y += ....o
> 
> -ifdef CONFIG_DTB_FILE
> +ifneq ($(CONFIG_DTB_FILE),"")
> obj-y += dtb.o
> -AFLAGS-y += -DCONFIG_DTB_FILE=\"$(CONFIG_DTB_FILE)\"
> endif
> 
> ALL_OBJS := $(TARGET_SUBARCH)/head.o $(ALL_OBJS)
> @@ -137,7 +136,7 @@ asm-offsets.s: $(TARGET_SUBARCH)/asm-offsets.c
> xen.lds: xen.lds.S
>       $(CPP) -P $(a_flags) -MQ $@ -o $@ $<
> 
> -dtb.o: $(CONFIG_DTB_FILE)
> +dtb.o: $(patsubst "%",%,$(CONFIG_DTB_FILE))
> 
> .PHONY: clean
> clean::
> diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
> index c404fa973e..50f019ed98 100644
> --- a/xen/arch/arm/arm32/head.S
> +++ b/xen/arch/arm/arm32/head.S
> @@ -156,10 +156,10 @@ past_zImage:
>         sub   r10, r9, r0            /* r10 := phys-offset */
> 
>         /* Using the DTB in the .dtb section? */
> -#ifdef CONFIG_DTB_FILE
> +.ifnes CONFIG_DTB_FILE,""
>         ldr   r8, =_sdtb
>         add   r8, r10                /* r8 := paddr(DTB) */
> -#endif
> +.endif
> 
>         /* Initialize the UART if earlyprintk has been enabled. */
> #ifdef CONFIG_EARLY_PRINTK
> diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
> index 5d44667bd8..f38a8dfca7 100644
> --- a/xen/arch/arm/arm64/head.S
> +++ b/xen/arch/arm/arm64/head.S
> @@ -296,9 +296,9 @@ real_start_efi:
>         sub   x20, x19, x0           /* x20 := phys-offset */
> 
>         /* Using the DTB in the .dtb section? */
> -#ifdef CONFIG_DTB_FILE
> +.ifnes CONFIG_DTB_FILE,""
>         load_paddr x21, _sdtb
> -#endif
> +.endif
> 
>         /* Initialize the UART if earlyprintk has been enabled. */
> #ifdef CONFIG_EARLY_PRINTK
> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> index 004b182acb..540a7ccc9d 100644
> --- a/xen/arch/arm/xen.lds.S
> +++ b/xen/arch/arm/xen.lds.S
> @@ -220,11 +220,9 @@ SECTIONS
>   } :text
>   _end = . ;
> 
> -#ifdef CONFIG_DTB_FILE
>   /* Section for the device tree blob (if any). */
> -  _sdtb = .;
> +  PROVIDE(_sdtb = .);
>   .dtb : { *(.dtb) } :text
> -#endif
> 
>   /* Sections to be discarded */
>   /DISCARD/ : {
> diff --git a/xen/common/Kconfig b/xen/common/Kconfig
> index eb953d171e..a1755cd380 100644
> --- a/xen/common/Kconfig
> +++ b/xen/common/Kconfig
> @@ -400,6 +400,16 @@ config DOM0_MEM
> 
>         Leave empty if you are not sure what to specify.
> 
> +config DTB_FILE
> +     string "Absolute path to device tree blob"
> +     depends on HAS_DEVICE_TREE
> +     help
> +       When using a bootloader that has no device tree support or when there
> +       is no bootloader at all, use this option to specify the absolute path
> +       to a device tree that will be linked directly inside Xen binary.
> +
> +       This is an optional config. Leave empty if not needed.
> +
> config TRACEBUFFER
>       bool "Enable tracing infrastructure" if EXPERT
>       default y
> -- 
> 2.29.0
> 




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.