[U-Boot] [PATCH v2] x86: zImage: pass device tree setup data to the kernel

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Fri, 2018-03-16 at 10:38 -0700, Ivan Gorinov wrote:
> On x86 platforms, U-Boot does not provide Device Tree data to the
> kernel.
> This prevents the kernel from using the same hardware description.
> 
> Make a copy of DTB data with setup_data header and insert new item
> into the the setup data linked list.

So, now is the question, what to do with x86 hardware that has DTS in U-
Boot, but uses ACPI tables, generated by U-Boot.

Would it work properly?

I would try to test it on Intel Edison (I hope you may do this yourself
as well), though I don't know when, have not much time to work with
Edison right now.

> Signed-off-by: Ivan Gorinov <ivan.gorinov@intel.com>
> ---
>  arch/x86/include/asm/bootparam.h |  1 +
>  arch/x86/lib/zimage.c            | 32
> ++++++++++++++++++++++++++++++++
>  2 files changed, 33 insertions(+)
> 
> diff --git a/arch/x86/include/asm/bootparam.h
> b/arch/x86/include/asm/bootparam.h
> index 90768a9..ea25cf7 100644
> --- a/arch/x86/include/asm/bootparam.h
> +++ b/arch/x86/include/asm/bootparam.h
> @@ -12,6 +12,7 @@
>  /* setup data types */
>  #define SETUP_NONE			0
>  #define SETUP_E820_EXT			1
> +#define SETUP_DTB			2
>  
>  /* extensible setup data list node */
>  struct setup_data {
> diff --git a/arch/x86/lib/zimage.c b/arch/x86/lib/zimage.c
> index 2a82bc8..41ad4c7 100644
> --- a/arch/x86/lib/zimage.c
> +++ b/arch/x86/lib/zimage.c
> @@ -14,6 +14,8 @@
>   */
>  
>  #include <common.h>
> +#include <malloc.h>
> +#include <asm/global_data.h>
>  #include <asm/acpi_table.h>
>  #include <asm/io.h>
>  #include <asm/ptrace.h>
> @@ -95,6 +97,35 @@ static int get_boot_protocol(struct setup_header
> *hdr)
>  	}
>  }
>  
> +static int setup_device_tree(struct setup_header *hdr)
> +{
> +	const void *fdt_blob = gd->fdt_blob;
> +	struct setup_data *sd;
> +	int size;
> +
> +	if (!fdt_blob)
> +		return 0;
> +
> +	size = fdt_totalsize(fdt_blob);
> +	if (size < 0)
> +		return -EINVAL;
> +
> +	size += sizeof(struct setup_data);
> +	sd = (struct setup_data *)malloc(size);
> +	if (!sd) {
> +		printf("Not enough memory for DTB setup data\n");
> +		return -ENOMEM;
> +	}
> +
> +	sd->next = hdr->setup_data;
> +	sd->type = SETUP_DTB;
> +	sd->len = fdt_totalsize(fdt_blob);
> +	memcpy(sd->data, fdt_blob, sd->len);
> +	hdr->setup_data = (unsigned long)sd;
> +
> +	return 0;
> +}
> +
>  struct boot_params *load_zimage(char *image, unsigned long
> kernel_size,
>  				ulong *load_addressp)
>  {
> @@ -262,6 +293,7 @@ int setup_zimage(struct boot_params *setup_base,
> char *cmd_line, int auto_boot,
>  #endif
>  
>  	setup_video(&setup_base->screen_info);
> +	setup_device_tree(hdr);
>  
>  	return 0;
>  }

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy