Re: [PATCH] add fdt prerequisites for arm64 UEFI Linux loader

[Francesco Lavra]

On 12/16/2013 02:52 PM, Leif Lindholm wrote:
> diff --git a/grub-core/lib/fdt.c b/grub-core/lib/fdt.c
> index 9f34dc7..fb13672 100644
> --- a/grub-core/lib/fdt.c
> +++ b/grub-core/lib/fdt.c
> @@ -423,3 +423,31 @@ int grub_fdt_set_prop (void *fdt, unsigned int 
> nodeoffset, const char *name,
>    grub_memcpy (prop + 3, val, len);
>    return 0;
>  }
> +
> +int
> +grub_fdt_create_empty_tree (void *fdt, unsigned int size)
> +{
> +  struct grub_fdt_empty_tree *et;
> +
> +  if (size < GRUB_FDT_EMPTY_TREE_SZ)
> +    return -1;
> +
> +  grub_memset (fdt, 0, size);
> +  et = fdt;
> +
> +  et->empty_node.node_end = grub_cpu_to_be32 (FDT_END);
> +  et->empty_node.prop_end = grub_cpu_to_be32 (FDT_END_NODE);
> +  et->empty_node.prop_start = grub_cpu_to_be32 (FDT_BEGIN_NODE);
> +  ((struct grub_fdt_empty_tree *) fdt)->header.off_mem_rsvmap =
> +    grub_cpu_to_be32 (ALIGN_UP (sizeof (grub_fdt_header_t), 8));
> +
> +  grub_fdt_set_off_dt_strings (fdt, sizeof (*et));
> +  grub_fdt_set_off_dt_struct (fdt, sizeof (grub_fdt_header_t) + 16);

I would write the offset as sizeof (et->header) + sizeof (et->empty_rsvmap)

> +  grub_fdt_set_version (fdt, FDT_SUPPORTED_VERSION);
> +  grub_fdt_set_last_comp_version (fdt, FDT_SUPPORTED_VERSION);
> +  grub_fdt_set_size_dt_struct (fdt, sizeof (et->empty_node));
> +  grub_fdt_set_totalsize (fdt, size);
> +  grub_fdt_set_magic (fdt, FDT_MAGIC);
> +
> +  return 0;
> +}
> diff --git a/include/grub/fdt.h b/include/grub/fdt.h
> index 2ad0536..bbc88ec 100644
> --- a/include/grub/fdt.h
> +++ b/include/grub/fdt.h
> @@ -36,6 +36,19 @@ typedef struct {
>       grub_uint32_t size_dt_struct;
>  } grub_fdt_header_t;
>  
> +struct grub_fdt_empty_tree {
> +  grub_fdt_header_t header;
> +  grub_uint64_t empty_rsvmap[2];
> +  struct {
> +    grub_uint32_t prop_start;
> +    grub_uint8_t name[1];
> +    grub_uint32_t prop_end;
> +    grub_uint32_t node_end;
> +  } empty_node;

Field names don't reflect their actual meaning: I would rename them as:

struct {
  grub_uint32_t node_start;
  grub_uint8_t name[1];
  grub_uint32_t node_end;
  grub_uint32_t tree_end;
} empty_tree;

--
Francesco