[U-Boot] [PATCH] fdt: Fix bug in size calculation in fdt_resize() with initrd use

[Jerry Van Baren]

On 08/03/2010 10:22 AM, Stefan Roese wrote:
> From: Feng Wang<fwang02 at harris.com>
>
> Original bug description from Feng (fdt_resize() bug caused "WARNING:
> could not set linux, initrd-start FDT_ERR_NOSPACE."):
>
> What I got is an error: "WARNING: could not set linux,initrd-start
> FDT_ERR_NOSPACE." after loading Device Tree blob. This in turn caused
> linux to miss init part.
>
> After some digging, I found out the reason for this error, it is caused
> by fdt_resize().
>
> FDT blob got resized after filling in all board specific information of
> PowerPC. (in boot_body_linux()). It reduced blob size with only extra
> space for two fdt_reserve_entry, one for fdt itself, and one for initrd.
> Then it's aligned to a 0x1000 page boundary. However, later in
> fdt_initrd(), it could add two more properties, initrd-start AND
> initrd-end, each one needs at least two fdt_reserve_entry sizes done by
> _fdt_add_property() (name and value). Thus, the two fdt_reserve_entry
> extra space is not sufficient.
>
> So for some specific fdt size which is just under the page boundary
> after resizing, this will cause an error of FDT_ERR_NOSPACE in
> fdt_initrd() when setting those two properties, and failed to pass
> initrd information to linux.
>
> My fix is in fdt_resize(), leave at least 4 fdt_reserve_entry for
> initrd. So instead of 2*sizeof(struct fdt_reserve_entry) for
> actual_totalsize, use 5*sizeof(struc fdt_reserve_entry).
>
> Stefan: I got this same error on katmai, when trying to boot with
> initrd (run flash_self). This patch fixes this issue.
>
> Signed-off-by: Feng Wang<fwang02 at harris.com>
> Tested-by: Stefan Roese<sr at denx.de>
> Cc: Jerry Van Baren<gvb.uboot at gmail.com>

Acked-by: Gerald Van Baren <vanbaren at cideas.com>

Stefan or Wolfgang, can you apply this?

Thanks,
gvb

> ---
>   common/fdt_support.c |    7 ++++---
>   1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/common/fdt_support.c b/common/fdt_support.c
> index 718b635..6f198de 100644
> --- a/common/fdt_support.c
> +++ b/common/fdt_support.c
> @@ -498,11 +498,12 @@ int fdt_resize(void *blob)
>
>   	/*
>   	 * Calculate the actual size of the fdt
> -	 * plus the size needed for two fdt_add_mem_rsv, one
> -	 * for the fdt itself and one for a possible initrd
> +	 * plus the size needed for 5 fdt_add_mem_rsv, one
> +	 * for the fdt itself and 4 for a possible initrd
> +	 * ((initrd-start + initrd-end) * 2 (name&  value))
>   	 */
>   	actualsize = fdt_off_dt_strings(blob) +
> -		fdt_size_dt_strings(blob) + 2*sizeof(struct fdt_reserve_entry);
> +		fdt_size_dt_strings(blob) + 5 * sizeof(struct fdt_reserve_entry);
>
>   	/* Make it so the fdt ends on a page boundary */
>   	actualsize = ALIGN(actualsize + ((uint)blob&  0xfff), 0x1000);