leon.nu Syndication

autofs and sshfs

2011-06-03T21:00:00Z

I'm working with remote servers and copy files via scp commands, almost every day. From time to time, there is need to mount them via sshfs filesystem, but it can be frustrating to repeat the same operations every time.

As everything in the linux world, the mount process can be fully automatic. It is really simple: use autofs.

I don't want to clone the guides, the internet is full of them, just want to add my insights:
1. automatic mount process is done under root privileges, so you will need to create SSH public key for the root and not for the user.
2. automapping configuration doesn't support dots as a path.

memcpy and memmove

2011-05-06T21:00:00Z

The patch from the Intel guys has exposed the bugs in code where developers ignored the requirement that the source and destination arrays passed to memcpy() cannot overlap.

It seems like a good time to remind you the difference between memcpy() and memmove(), don't fail like Adobe did.

The memcpy() function copies n bytes from memory area src to memory area dest. The memory areas should not overlap.
The memmove() function copies n bytes from memory area src to memory area dest. The memory areas may overlap: copying takes place as though the bytes in src are first copied into a temporary array that does not overlap src or dest, and the bytes are then copied from the temporary array to dest.

can't access tty

2011-04-17T21:00:00Z

Follow up on my earlier post, about the error during recovery and update processes.

/bin/sh: can't access tty: job control turned off

The source of this error is incorrect init file from the recovery partition.

Just to remind you that the partition table of Toshiba AC100-118 has 13 partitions:

Partition 2 - BCT - boot config table
Partition 3 - PT - partition table
Partition 4 - EBT - bootloader
Partition 5 - SOS - recovery partition
Partition 6 - LNX - linux system
Partition 7 - MBR - master boot record
Partition 8 - APP - applications (/system)
Partition 9 - CAC - cache (/cache)
Partition 10 - MSC - miscellaneous (/misc)
Partition 11 - EM1 - partition table
Partition 12 - UDA - user data (/data)
Partition 13 - EM2 - partition table
Partition 14 - UDB - user storage (/storage)

In very few words, I'll try to explain how to fix it. I assume you already know what is nvflash utility and how to work with it.

Backup

First of all we start from the backup. We are going to change the recovery partition, so it is the one we are going to save, but I strongly recommend to save ALL partitions.

LD_LIBRARY_PATH=. ./nvflash --bl ../prebuilt/fastboot.stock.bin --go
LD_LIBRARY_PATH=. ./nvflash -r --getpartitiontable partitiontable.txt
LD_LIBRARY_PATH=. ./nvflash -r --read 5 part-5.img

Copy the Image

Copy part-5.img file you downloaded to any folder far away from your backup, and work only there.

Unpacking

The unpack_bootimg tool was written by Phh. The compiled version can be found on my site.

./unpack_bootimg part-5.img
mkdir ramdisk
zcat initrd.img | ( cd ramdisk; cpio -i )

Editing

Make changes in the init file, located under ramdisk folder. Change the following line:

for dev in mmcblk1p1 mmcblk1p2 mmcblk1p3 sda1 sda2 sda3:do

to be

for dev in mmcblk0p1 mmcblk0p2 mmcblk0p3 sda1 sda2 sda3:do

Re-Packing the images

The make_bootimg tool was written by Phh, and mkbootfs was taken from the Android SDK source. The compiled versions can be found on my site. The command line of the make_bootimg tool must be according to the model you are using.

cd ..
mkbootfs ./ramdisk | gzip > ramdisk-new.img
./make_bootimg part-5.img zImage ramdisk-new.img -c 'mem=448M@0M nvmem=64M@448M 
vmalloc=320M video=tegrafb console=tty0 usbcore.old_scheme_first=1 quiet splash
tegraboot=sdmmc tegrapart=recovery:300:a00:800,boot:d00:1000:800,mbr:1d00:200:800'

Restore the partition

Use [StartSector], [NumSectors] from the partitiontable.txt you saved at the backup stage.

LD_LIBRARY_PATH=. ./nvflash --bl fastboot.bin --go
LD_LIBRARY_PATH=. ./nvflash -r --rawdevicewrite [StartSector] [NumSectors] part-[PartitionId].img
LD_LIBRARY_PATH=. ./nvflash -r --rawdevicewrite [StartSector] [NumSectors] part-2.img

Linux 4 Tegra (L4T) Removed

2011-04-16T21:00:00Z

Mar 25 2011 at 6:12 PM We have removed the L4T downloads from the site due to some bugs and while we prepare for a forthcoming release. Please continue to report if you are having issues (or successes).

Nvidia removed from their web site the Linux 4 Tegra (L4T). This package enebled to the developers to program Linux on Nvidia Tegra 250 based platforms.

Toshiba AC100 & Android 2.1 (Eclair)

2011-04-15T21:00:00Z

Yesterday, I received the Toshiba AC100 netbook. The specification and reviews look promising too, but the reailty was less shiny.

First of all, my computer arrived with more than one keyboard layout. In my case default layout was not english, and it took me time to realize how it can be changed. If you new to the Android based netbook, know the magic combination is CTRL + BACKSPACE.

After I succesfully changed the keyboard layout, the second problem arised. The connection to my WiFi access point was dropped after a couple of seconds. If you suffer from continious disconnects, try to change channel on your router to be channel 1. It helped me.

And third, the most important and less funny, Right after factory reset or operating system update you can can receive the error:

/bin/sh: can't access tty: job control turned off

This error is caused by incorrect init file and the line:

for dev in mmcblk1p1 mmcblk1p2 mmcblk1p3 sda1 sda2 sda3:do

must be changed to

for dev in mmcblk0p1 mmcblk0p2 mmcblk0p3 sda1 sda2 sda3:do