From: Thomas Huth <thuth@redhat•com>
To: Nikunj A Dadhania <nikunj@linux•vnet.ibm.com>
Cc: linuxppc-dev@ozlabs•org, segher@kernel•crashing.org,
aik@ozlabs•ru, dvaleev@suse•com
Subject: Re: [PATCH SLOF v2 4/5] disk-label: introduce helper to check fat filesystem
Date: Mon, 29 Jun 2015 10:47:16 +0200 [thread overview]
Message-ID: <20150629104716.61aced97@thh440s> (raw)
In-Reply-To: <1435214729-15952-5-git-send-email-nikunj@linux.vnet.ibm.com>
On Thu, 25 Jun 2015 12:15:28 +0530
Nikunj A Dadhania <nikunj@linux•vnet.ibm.com> wrote:
> Signed-off-by: Nikunj A Dadhania <nikunj@linux•vnet.ibm.com>
> ---
> slof/fs/packages/disk-label.fs | 17 +++++++++--------
> 1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/slof/fs/packages/disk-label.fs b/slof/fs/packages/disk-label.fs
> index 0995808..7ed5526 100644
> --- a/slof/fs/packages/disk-label.fs
> +++ b/slof/fs/packages/disk-label.fs
> @@ -321,6 +321,14 @@ CONSTANT /gpt-part-entry
>
> \ Load from first active DOS boot partition.
>
> +: fat-bootblock? ( addr -- flag )
> + \ byte 0-2 of the bootblock is a jump instruction in
> + \ all FAT filesystems.
> + \ e9 and eb are jump instructions in x86 assembler.
> + dup c@ e9 = IF drop true EXIT THEN
> + dup c@ eb = swap 2+ c@ 90 = and
> +;
> +
> \ NOTE: block-size is always 512 bytes for DOS partition tables.
>
> : load-from-dos-boot-partition ( addr -- size )
> @@ -549,14 +557,7 @@ AA268B49521E5A8B CONSTANT GPT-PREP-PARTITION-4
> : try-dos-files ( -- found? )
> no-mbr? IF false EXIT THEN
>
> - \ disk-buf 0 byte 0-2 is a jump instruction in all FAT
> - \ filesystems.
> - \ e9 and eb are jump instructions in x86 assembler.
> - disk-buf c@ e9 <> IF
> - disk-buf c@ eb <>
> - disk-buf 2+ c@ 90 <> or
> - IF false EXIT THEN
> - THEN
> + disk-buf fat-bootblock? 0= IF false EXIT THEN
> s" fat-files" (interpose-filesystem)
> true
> ;
Reviewed-by: Thomas Huth <thuth@redhat•com>
next prev parent reply other threads:[~2015-06-29 8:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-25 6:45 [PATCH SLOF v2 0/5] GPT fixes/cleanup and LVM support with FAT Nikunj A Dadhania
2015-06-25 6:45 ` [PATCH SLOF v2 1/5] disk-label: simplify gpt-prep-partition? routine Nikunj A Dadhania
2015-06-25 6:45 ` [PATCH SLOF v2 2/5] introduce 8-byte LE helpers Nikunj A Dadhania
2015-06-25 6:45 ` [PATCH SLOF v2 3/5] disk-label: rename confusing "block" word Nikunj A Dadhania
2015-06-29 8:44 ` Thomas Huth
2015-06-25 6:45 ` [PATCH SLOF v2 4/5] disk-label: introduce helper to check fat filesystem Nikunj A Dadhania
2015-06-29 8:47 ` Thomas Huth [this message]
2015-06-25 6:45 ` [PATCH SLOF v2 5/5] disk-label: add support for booting from GPT FAT partition Nikunj A Dadhania
2015-06-29 9:17 ` Thomas Huth
2015-06-29 11:13 ` Nikunj A Dadhania
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