Date: Fri, 8 Apr 2011 09:57:12 +0200 From: Milan Obuch <freebsd-mips@dino.sk> To: Aleksandr Rybalko <ray@ddteam.net> Cc: freebsd-mips@freebsd.org Subject: Re: [RFC] Re: TP link MR3220 status, boot from flash via u-boot question Message-ID: <20110408095712.1fc36066@atom.dino.sk> In-Reply-To: <20110401005733.3598e82c.ray@ddteam.net> References: <20110331101554.68171eed@atom.dino.sk> <AANLkTik9r7XZn2yyJe37EXYXfgkUzyt5Ne-eKd_XqGMO@mail.gmail.com> <20110331142640.07f2101b@atom.dino.sk> <20110401005733.3598e82c.ray@ddteam.net>
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On Fri, 1 Apr 2011 00:57:33 +0300, Aleksandr Rybalko <ray@ddteam.net>
wrote:
> On Thu, 31 Mar 2011 14:26:40 +0200
> Milan Obuch <freebsd-mips@dino.sk> wrote:
>
> > On Thu, 31 Mar 2011 18:39:36 +0800, Adrian Chadd
> > <adrian@freebsd.org> wrote:
[ snip ]
> > Hi,
> > I am watching freebsd-wifi-build on googlecode and just noticed new
> > config there... Is your 11n wifi already working too? I would be
> > glad to compare your results with mine, so we could unify our
> > efforts. Right now, kernel load from flash in u-boot is a show
> > stopper for me, so if you could address this one first, it would
> > help me really much.
>
> Draft for wiki page 'Run from NOR flash with U-Boot'
>
In my case, to be exact, there is SPI flash, actually...
> Keywords: U-Boot, embedded
>
> 1. Ask U-Boot: "what do you support to boot?"
>
> Normally, U-Boot use special image for kernel/ramfs packing. But we
> need to know which compression support U-Boot that fleshed to our
> target board.
>
This one is easy - I can use gzip packed kernel only. If I try other
compressing method, u-boot complains with 'bad gzip data' message so
this one is clear in this case, I think.
> First way:
> use mkimage utility (/usr/ports/devel/u-boot) and make test
> images for all supported by mkimage compression types.
> <code>
> mkimage -A ${TARGET} -O linux -T kernel \
> -C ${COMPRESSION_TYPE} \
> -a ${RAM_START_ADDRESS} \
> -e ${RAM_START_ADDRESS} \
> -n 'FreeBSD Kernel Image' \
> -d SOME_SMALL_FILE_NAME \
> test.uboot
> </code>
> Then for each file, do transfer to board and run from image with
> `bootm' command. And check what U-Boot answer you, if answer like
> "Unimplemented compression type ?", then you know :).
>
> Second way:
> From running Linux or U-Boot get first 64k block from kernel partition
> in flash.
>
> Break your mkimage utility: avoid exit when we do "show info" (key -i)
> CRC failed. And check compression type of 64k file we get from device.
>
> Or just delete U-Boot image header from file
> <code>
> dd if=64k.file of=just_kern bs=64 skip=1
> </code>
> and check with file(1) utility
>
> 2. Create image
> 2.1. More canonical way, we have mkimage, gzip or bz2 and compiled
> kernel, maybe kernel.bin also.
>
> <code>
> gzip --best --force vmlinux.bin
> </code>
>
> for ELF kernel:
> <code>
> mkimage -A mips -O linux -T kernel \
> -C gzip \
> -a ${LOAD_ADDRESS} \
> -e ${START_ADDRESS} \
> -n 'FreeBSD Kernel Image' \
> -d kernel \
> kernel.uboot
> </code>
> LOAD_ADDRESS - in most cases this is RAM base address
> START_ADDRESS = LOAD_ADDRESS + ELF_HEADER_SIZE (0x1000 for ELF image)
>
> for kernel.bin:
>
> LOAD_ADDRESS = RAM_BASE_ADDRESS + 0x1000
> START_ADDRESS = RAM_BASE_ADDRESS + 0x1000
>
> Don't forget to check/change KERNLOADADDR of kernel config file.
> KERNLOADADDR must be equal to START_ADDRESS.
>
I tried it various way, no success yet. When I load kernel via TFTP to
address set in kernel config (0x80050000 in my case) I can issue a go
command to 'start' address, usually 0x80050100, but sometimes it is
0x80050120 - I am checking for this after kernel is built - and kernel
boots correctly and works.
As already mentioned, there is a mktplinkfw utility, which combines
kernel and root fs (or uses kernel with embedded root fs), prepends a
required header and pads generated image to full size of flash minus
128 kB for u-boot itself. I am able to flash such image into flash, but
bootm tells only about success uncompressing kernel, starting kernel
and that's all.
## Booting image at 9f020000 ...
Uncompressing Kernel Image ... OK
Starting kernel ...
Nothing more, powerdown necessary to start again.
> 2.2. Longest way, but have smallest footprint, used only if
> U-Boot support LZMA.
>
> Problem 1: Current version of mkimage from ports, don't support LZMA.
> So we need new: http://my.ddteam.net/files/u-boot.new.tar.gz
>
> Problem 2: Devices I know support only old LZMA.
> I use LZMA 4.17.
>
> Then mkimage, like in 2.2., but -C lzma.
>
> 3. Now we have kernel U-Boot image, so transfer it to device and try
> with `bootm' command.
>
> 4. If all fine, write image to flash kernel partition.
>
>
> Hope this help :)
>
[ snip ]
Not much yet, unfortunatelly...
On a side note, there is one thing to be addressed. As my device has
only 4 MB flash, I still need to shrink the image I would like to use
there. I could put there working kernel, when flash boot issue is
solved, but root fs not yet, together they do not fit. I still need to
save as much as 600 kB of space... Do you have any tips to share? In
some older mails here I saw you managed to do it for other device...
Regards,
Milan
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