[OpenWrt-Devel,2/3] ath79: fix IMAGE_SIZE for common TP-Link definitions
diff mbox series

Message ID 20190806131039.51484-2-freifunk@adrianschmutzler.de
State New
Headers show
Series
  • [OpenWrt-Devel,1/3] ath79: tidy up and fix IMAGE_SIZE for Ubiquiti devices
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Commit Message

Adrian Schmutzler Aug. 6, 2019, 1:10 p.m. UTC
So far, IMAGE_SIZE is set as follows:
tplink-4m*   3904k  0x3d0000
tplink-8m*   7936k  0x7c0000
tplink-16m* 15872k  0xf80000

However, based on the size of firmware partitions in DTS it should
be:
tplink-4m*   3904k  0x3d0000
tplink-8m*   8000k  0x7d0000
tplink-16m* 16192k  0xfd0000

All (!) 8m*/16m* devices actually follow the latter scheme, which
is also consistent in terms of left free space for other
partitions. Thus, fix it.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
---
 target/linux/ath79/image/common-tp-link.mk | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Tom Psyborg Aug. 7, 2019, 3:57 p.m. UTC | #1
Hi

Looks like there were many doubts about image size over the years.

One thing that should be considered is use of OEM firmware, either in
case of just a single revert after OpenWrt flashing, or multiple
reverts/switching between OEM/OpenWrt firmwares.

Relevant in this case is config partition within OEM fw, and by
specifying OpenWrt image size to occupy all available flash space
between u-boot and art partitions destroys config contents which may
turn up very impractical for those that do frequent switching between
the two.

Further, config partition size also varies from device to device, some
have it 64KB others 128KB in size, at least what I observed with my
devices.

So, the correct image size for Archer C7 v1 turned out to be 0x7b0000

On 06/08/2019, Adrian Schmutzler <freifunk@adrianschmutzler.de> wrote:
> So far, IMAGE_SIZE is set as follows:
> tplink-4m*   3904k  0x3d0000
> tplink-8m*   7936k  0x7c0000
> tplink-16m* 15872k  0xf80000
>
> However, based on the size of firmware partitions in DTS it should
> be:
> tplink-4m*   3904k  0x3d0000
> tplink-8m*   8000k  0x7d0000
> tplink-16m* 16192k  0xfd0000
>
> All (!) 8m*/16m* devices actually follow the latter scheme, which
> is also consistent in terms of left free space for other
> partitions. Thus, fix it.
>
> Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
> ---
>  target/linux/ath79/image/common-tp-link.mk | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/target/linux/ath79/image/common-tp-link.mk
> b/target/linux/ath79/image/common-tp-link.mk
> index da4616482a..d05ac028c7 100644
> --- a/target/linux/ath79/image/common-tp-link.mk
> +++ b/target/linux/ath79/image/common-tp-link.mk
> @@ -83,19 +83,19 @@ endef
>  define Device/tplink-8m
>    $(Device/tplink-nolzma)
>    TPLINK_FLASHLAYOUT := 8M
> -  IMAGE_SIZE := 7936k
> +  IMAGE_SIZE := 8000k
>  endef
>
>  define Device/tplink-8mlzma
>    $(Device/tplink)
>    TPLINK_FLASHLAYOUT := 8Mlzma
> -  IMAGE_SIZE := 7936k
> +  IMAGE_SIZE := 8000k
>  endef
>
>  define Device/tplink-16mlzma
>    $(Device/tplink)
>    TPLINK_FLASHLAYOUT := 16Mlzma
> -  IMAGE_SIZE := 15872k
> +  IMAGE_SIZE := 16192k
>  endef
>
>  define Device/tplink-safeloader
> --
> 2.20.1
>
>
> _______________________________________________
> openwrt-devel mailing list
> openwrt-devel@lists.openwrt.org
> https://lists.openwrt.org/mailman/listinfo/openwrt-devel
>
Adrian Schmutzler Aug. 7, 2019, 4:17 p.m. UTC | #2
> -----Original Message-----
> From: openwrt-devel [mailto:openwrt-devel-bounces@lists.openwrt.org] On Behalf Of Tom Psyborg
> Sent: Mittwoch, 7. August 2019 17:58
> To: Adrian Schmutzler <freifunk@adrianschmutzler.de>
> Cc: openwrt-devel@lists.openwrt.org
> Subject: Re: [OpenWrt-Devel] [PATCH 2/3] ath79: fix IMAGE_SIZE for common TP-Link definitions
> 
> Hi
> 
> Looks like there were many doubts about image size over the years.
> 
> One thing that should be considered is use of OEM firmware, either in
> case of just a single revert after OpenWrt flashing, or multiple
> reverts/switching between OEM/OpenWrt firmwares.
> 
> Relevant in this case is config partition within OEM fw, and by
> specifying OpenWrt image size to occupy all available flash space
> between u-boot and art partitions destroys config contents which may
> turn up very impractical for those that do frequent switching between
> the two.
> 
> Further, config partition size also varies from device to device, some
> have it 64KB others 128KB in size, at least what I observed with my
> devices.
> 
> So, the correct image size for Archer C7 v1 turned out to be 0x7b0000

But wouldn't this call for introducing a config partition for the C7 v1?
I'm not sure how your analysis is affecting the IMAGE_SIZE discussion (unless you say TP-Link devices generally have this config partition with different sizes, and thus the whole concept of including IMAGE_SIZE in common definitions is "wrong")...

Best

Adrian
Tom Psyborg Aug. 7, 2019, 9:19 p.m. UTC | #3
Correct me if I'm wrong but I thought all the data beyond IMAGE_SIZE
remain intact by OpenWrt on firstboot. Experimenting with Archer C7 v1
recently I was able to flash OpenWrt image (ar71xx) and after
reflashing tplink fw previous settings were still valid indicating
config partition hasn't been overwritten.
At least TL-MR22U has config partition of 64KB and Archer C7 has 128KB
- I've gone through GPL sources of Archer and it seems between two
firmware versions this partition was increased from 64 to 128KB,
actually I discovered this by hexdiff-ing u-boot versions from each
firmware version

On 07/08/2019, Adrian Schmutzler <mail@adrianschmutzler.de> wrote:
>> -----Original Message-----
>> From: openwrt-devel [mailto:openwrt-devel-bounces@lists.openwrt.org] On
>> Behalf Of Tom Psyborg
>> Sent: Mittwoch, 7. August 2019 17:58
>> To: Adrian Schmutzler <freifunk@adrianschmutzler.de>
>> Cc: openwrt-devel@lists.openwrt.org
>> Subject: Re: [OpenWrt-Devel] [PATCH 2/3] ath79: fix IMAGE_SIZE for common
>> TP-Link definitions
>>
>> Hi
>>
>> Looks like there were many doubts about image size over the years.
>>
>> One thing that should be considered is use of OEM firmware, either in
>> case of just a single revert after OpenWrt flashing, or multiple
>> reverts/switching between OEM/OpenWrt firmwares.
>>
>> Relevant in this case is config partition within OEM fw, and by
>> specifying OpenWrt image size to occupy all available flash space
>> between u-boot and art partitions destroys config contents which may
>> turn up very impractical for those that do frequent switching between
>> the two.
>>
>> Further, config partition size also varies from device to device, some
>> have it 64KB others 128KB in size, at least what I observed with my
>> devices.
>>
>> So, the correct image size for Archer C7 v1 turned out to be 0x7b0000
>
> But wouldn't this call for introducing a config partition for the C7 v1?
> I'm not sure how your analysis is affecting the IMAGE_SIZE discussion
> (unless you say TP-Link devices generally have this config partition with
> different sizes, and thus the whole concept of including IMAGE_SIZE in
> common definitions is "wrong")...
>
> Best
>
> Adrian
>
Adrian Schmutzler Aug. 7, 2019, 9:30 p.m. UTC | #4
> -----Original Message-----
> From: Tom Psyborg [mailto:pozega.tomislav@gmail.com]
> Sent: Mittwoch, 7. August 2019 23:19
> To: Adrian Schmutzler <mail@adrianschmutzler.de>
> Cc: openwrt-devel@lists.openwrt.org
> Subject: Re: [OpenWrt-Devel] [PATCH 2/3] ath79: fix IMAGE_SIZE for
> common TP-Link definitions
> 
> Correct me if I'm wrong but I thought all the data beyond IMAGE_SIZE
> remain intact by OpenWrt on firstboot. Experimenting with Archer C7 v1
> recently I was able to flash OpenWrt image (ar71xx) and after reflashing
> tplink fw previous settings were still valid indicating config partition hasn't
> been overwritten.
> At least TL-MR22U has config partition of 64KB and Archer C7 has 128KB
> - I've gone through GPL sources of Archer and it seems between two
> firmware versions this partition was increased from 64 to 128KB, actually I
> discovered this by hexdiff-ing u-boot versions from each firmware version

Nevertheless, addressing this with IMAGE_SIZE would still be just a hack.

If there is config data to be preserved, one should add a partition for it. Then IMAGE_SIZE would just shrink according to the (then correct) firmware partition. Now that we have DTS files with individual partition schemes, this would be even easier than for ar71xx.

Best

Adrian
Adrian Schmutzler Aug. 8, 2019, 11:12 a.m. UTC | #5
> > Correct me if I'm wrong but I thought all the data beyond IMAGE_SIZE 
> > remain intact by OpenWrt on firstboot. Experimenting with Archer C7 v1 
> > recently I was able to flash OpenWrt image (ar71xx) and after reflashing 
> > tplink fw previous settings were still valid indicating config partition hasn't 
> > been overwritten. 
> > At least TL-MR22U has config partition of 64KB and Archer C7 has 128KB 
> > - I've gone through GPL sources of Archer and it seems between two 
> > firmware versions this partition was increased from 64 to 128KB, actually I 
> > discovered this by hexdiff-ing u-boot versions from each firmware version 
> Nevertheless, addressing this with IMAGE_SIZE would still be just a hack. 
> If there is config data to be preserved, one should add a partition for it. Then IMAGE_SIZE would just shrink according to the (then correct) firmware partition. Now that we have DTS files with individual partition > schemes, this would be even easier than for ar71xx.
> Best 
> Adrian 

To put this in a more positive frame:

If you think that there is a config partition on C7v1 or other devices and you know where it is, please send a patch adding it as read-only partition in DTS.

Best

Adrian

Patch
diff mbox series

diff --git a/target/linux/ath79/image/common-tp-link.mk b/target/linux/ath79/image/common-tp-link.mk
index da4616482a..d05ac028c7 100644
--- a/target/linux/ath79/image/common-tp-link.mk
+++ b/target/linux/ath79/image/common-tp-link.mk
@@ -83,19 +83,19 @@  endef
 define Device/tplink-8m
   $(Device/tplink-nolzma)
   TPLINK_FLASHLAYOUT := 8M
-  IMAGE_SIZE := 7936k
+  IMAGE_SIZE := 8000k
 endef
 
 define Device/tplink-8mlzma
   $(Device/tplink)
   TPLINK_FLASHLAYOUT := 8Mlzma
-  IMAGE_SIZE := 7936k
+  IMAGE_SIZE := 8000k
 endef
 
 define Device/tplink-16mlzma
   $(Device/tplink)
   TPLINK_FLASHLAYOUT := 16Mlzma
-  IMAGE_SIZE := 15872k
+  IMAGE_SIZE := 16192k
 endef
 
 define Device/tplink-safeloader