Subject: Re: [PATCH SLOF v4 1/4] disk-label: simplify gpt-prep-partition? routine

From: Alexey Kardashevskiy <[email-masked]>
Date: Sat, 4 Jul 2015 11:42:45 +1000

On 07/02/2015 09:35 PM, Nikunj A Dadhania wrote:
> Signed-off-by: Nikunj A Dadhania <[email-masked]>
> Reviewed-by: Thomas Huth <[email-masked]>

If it does not change SLOF behaviour in any way (and it does not, right?), 
it would be nice to see in the commit log.

> ---
>   slof/fs/packages/disk-label.fs | 41 +++++++++++++++--------------------------
>   1 file changed, 15 insertions(+), 26 deletions(-)
>
> diff --git a/slof/fs/packages/disk-label.fs b/slof/fs/packages/disk-label.fs
> index fe1c25e..f1f083a 100644
> --- a/slof/fs/packages/disk-label.fs
> +++ b/slof/fs/packages/disk-label.fs
> @@ -352,42 +352,31 @@ CONSTANT /gpt-part-entry
>      drop 0
>   ;
>
> -\ Check for GPT PReP partition GUID
> -9E1A2D38     CONSTANT GPT-PREP-PARTITION-1
> -C612         CONSTANT GPT-PREP-PARTITION-2
> -4316         CONSTANT GPT-PREP-PARTITION-3
> -AA26         CONSTANT GPT-PREP-PARTITION-4
> -8B49521E5A8B CONSTANT GPT-PREP-PARTITION-5
> +\ Check for GPT PReP partition GUID. Only first 3 blocks are
> +\ byte-swapped treating last two blocks as contigous for simplifying
> +\ comparison
> +9E1A2D38            CONSTANT GPT-PREP-PARTITION-1
> +C612                CONSTANT GPT-PREP-PARTITION-2
> +4316                CONSTANT GPT-PREP-PARTITION-3
> +AA268B49521E5A8B    CONSTANT GPT-PREP-PARTITION-4
>
>   : gpt-prep-partition? ( -- true|false )
> -   block gpt-part-entry>part-type-guid l@-le GPT-PREP-PARTITION-1 = IF
> -      block gpt-part-entry>part-type-guid 4 + w@-le
> -      GPT-PREP-PARTITION-2 = IF
> -         block gpt-part-entry>part-type-guid 6 + w@-le
> -         GPT-PREP-PARTITION-3 = IF
> -            block gpt-part-entry>part-type-guid 8 + w@
> -            GPT-PREP-PARTITION-4 = IF
> -               block gpt-part-entry>part-type-guid a + w@
> -               block gpt-part-entry>part-type-guid c + l@ swap lxjoin
> -               GPT-PREP-PARTITION-5 = IF
> -                   TRUE EXIT
> -               THEN
> -            THEN
> -         THEN
> -      THEN
> -   THEN
> -   FALSE
> +   block gpt-part-entry>part-type-guid
> +   dup l@-le     GPT-PREP-PARTITION-1 <> IF drop false EXIT THEN
> +   dup 4 + w@-le GPT-PREP-PARTITION-2 <> IF drop false EXIT THEN
> +   dup 6 + w@-le GPT-PREP-PARTITION-3 <> IF drop false EXIT THEN
> +       8 + x@    GPT-PREP-PARTITION-4 =
>   ;
>
>   : load-from-gpt-prep-partition ( addr -- size )
> -   no-gpt? IF drop FALSE EXIT THEN
> +   no-gpt? IF drop false EXIT THEN
>      debug-disk-label? IF
>         cr ." GPT partition found " cr
>      THEN
>      1 read-sector block gpt>part-entry-lba l@-le
>      block-size * to seek-pos
>      block gpt>part-entry-size l@-le to gpt-part-size
> -   block gpt>num-part-entry l@-le dup 0= IF FALSE EXIT THEN
> +   block gpt>num-part-entry l@-le dup 0= IF false EXIT THEN
>      1+ 1 ?DO
>         seek-pos 0 seek drop
>         block gpt-part-size read drop gpt-prep-partition? IF
> @@ -405,7 +394,7 @@ AA26         CONSTANT GPT-PREP-PARTITION-4
>         THEN
>         seek-pos gpt-part-size i * + to seek-pos
>      LOOP
> -   FALSE
> +   false
>   ;
>
>   \ Extract the boot loader path from a bootinfo.txt file
>

-- 
Alexey