Is LiveMMC or Live SD possible?

[AS]

Hmm before I do anything, please confirm that what I am doing is correct:

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#dd if=/dev/zero of=/dev/mmcblk0p1
TIA

I think you should zero-out also the partition table, than use the device istead of the partition, also bs=1M is suggested for improved speed:

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#dd if=/dev/zero of=/dev/mmcblk0 bs=1M

[Just17]

As above ......  zero out the first sector .....  and the 1M will do that ....  so use the device name as AS pointed out.
Your device name from a previous post is  /dev/mmcblk0

[Archie]

OK. Done following AS' instructions.

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# dd if=/dev/zero of=/dev/mmcblk0 bs=1M
dd: writing `/dev/mmcblk0': No space left on device
15097+0 records in
15096+0 records out
15829303296 bytes (16 GB) copied, 76.4745 s, 207 MB/s
Ejected and reinserted the MicroSD.

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# fdisk /dev/mmcblk
n > 2048 > 2050 // very small partition
n > 2051 > Enter
t > 1 > c
p
Disk /dev/mmcblk0: 15.8 GB, 15829303296 bytes
4 heads, 16 sectors/track, 483072 cylinders, total 30916608 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x7a71191c

        Device Boot      Start         End      Blocks   Id  System
/dev/mmcblk0p1            2048        2050           1+   c  W95 FAT32 (LBA)
/dev/mmcblk0p2            2051    30916607    15457278+  83  Linux

w
The partition table has been altered!

Calling ioctl() to re-read partition table.

[b]WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
information.[/b]                                                                              // What's this?
Syncing disks.
# exit

So that seemed OK. I ejected the MicroSD ...

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$ lusbc
...

Reinserted the MicroSD then clicked Yes.

Found 2 partitions ... I selected /dev/mmcblk0p2 and clicked OK.

It is asking me to select again between the 2 partitions. ;(

... and I'm stuck.


EDIT:

As above ......  zero out the first sector .....  and the 1M will do that ....  so use the device name as AS pointed out.
Your device name from a previous post is  /dev/mmcblk0

Yes, it musta changed when I reinserted at some time. It is /dev/mmcblk0.

[coco]

You can install PCLOS on an SD card (in a USB port) as if on a hard drive and boot from the SD card. You can also install PCLOS on a SD card as a liveSD, for example, with software unetbooting. With liveSD can not save changes to the PCLOS.

If you have a fast SD card, the result is pretty good.

[Archie]

You can install PCLOS on an SD card (in a USB port) as if on a hard drive and boot from the SD card. You can also install PCLOS on a SD card as a liveSD, for example, with software unetbooting. With liveSD can not save changes to the PCLOS.

If you have a fast SD card, the result is pretty good.

Well that's an idea. I'll dig around my basket for that small USB adaptor, and see what comes out of it.

[Just17]

Did you deliberately format the Linux partition ....  and to what?

I saw no mention of formatting .....  hence the question ....

[AS]

Disk /dev/mmcblk0: 15.8 GB, 15829303296 bytes
4 heads, 16 sectors/track, 483072 cylinders, total 30916608 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x7a71191c

... a zeroed block should lead to 0x00000000 .... 

[Archie]

I took coco's suggestion and was able to format the MicroSD via the adaptor on PCC. Copied a remaster from last year using LUSBC ... and am now just waiting for a build to finish so I can reboot and test whether I can boot from the card reader or if I would still need to use the adapter.

I'm not sure why zero-out did those and I can't remember if I formatted the card after zero-out... too many things! Sorry, guys.

I'll post the results after a reboot.

[AS]

I took coco's suggestion and was able to format the MicroSD via the adaptor on PCC. Copied a remaster from last year using LUSBC ...

If successful, that should confirm an issue with mmc support from kernel ...

[Archie]

Well, my BIOS did not support booting from the card reader but I was able to boot using the USB adapter and the boot speed and reaction time was also fast and acceptable.

I took coco's suggestion and was able to format the MicroSD via the adaptor on PCC. Copied a remaster from last year using LUSBC ...

If successful, that should confirm an issue with mmc support from kernel ...

Yeap.

[Just17]

Well, my BIOS did not support booting from the card reader but I was able to boot using the USB adapter and the boot speed and reaction time was also fast and acceptable.

Is your card reader not attached to a USB port in the PC?

If not, how is it attached?

Thanks.

BTW ......  congrats on getting it working 

[coco]

I took coco's suggestion and was able to format the MicroSD via the adaptor on PCC. Copied a remaster from last year using LUSBC ... and am now just waiting for a build to finish so I can reboot and test whether I can boot from the card reader or if I would still need to use the adapter.

I'm not sure why zero-out did those and I can't remember if I formatted the card after zero-out... too many things! Sorry, guys.

I'll post the results after a reboot.

Archie I have used this form of testing PCLOS since summer 2010, I take the livecd and install PCLOS on usb memory like a hard drive, putting in the usb ext4 partition, swap and the MBR, then select the bios to boot from the USB (with adapter if is an SD card).

If the iso is 32bit use Virtual Box to boot the livecd and install, if the iso is 64bits use Unetbooting o
LinuxLive USB Creator to create a liveusb and then boot from the liveusb (with other usb memory where the system was installed) and install 64bit version in the other usb memory.

Normally no BIOS supports booting from the card reader.

Sorry for my bad english.

[Just17]

Some relevant info  ....

Personal computers
Although many personal computers accommodate SD cards as an auxiliary storage device through a built-in slot or a USB adaptor, SD cards cannot be used as the primary hard disk through the onboard ATA controller because none of the SD card variants supports ATA signalling. This use requires a separate SD controller chip[46] or a SD-to-CompactFlash converter. However, on computers that support bootstrapping from a USB interface, an SD card in a USB adaptor can be the primary hard disk, provided it contains an operating system that supports USB access once the bootstrap is complete.

This is why it only works from USB hub.



http://en.wikipedia.org/wiki/Secure_Digital

[AS]

Some relevant info  ....

Personal computers
Although many personal computers accommodate SD cards as an auxiliary storage device through a built-in slot or a USB adaptor, SD cards cannot be used as the primary hard disk through the onboard ATA controller because none of the SD card variants supports ATA signalling. This use requires a separate SD controller chip[46] or a SD-to-CompactFlash converter. However, on computers that support bootstrapping from a USB interface, an SD card in a USB adaptor can be the primary hard disk, provided it contains an operating system that supports USB access once the bootstrap is complete.

This is why it only works from USB hub.

http://en.wikipedia.org/wiki/Secure_Digital

I can confirm about, my  laptop is using a PCI adapter, that cannot be used as boot device:

08:05.2 SD Host controller: O2 Micro, Inc. Integrated MMC/SD Controller (rev 02)
08:05.3 Mass storage controller: O2 Micro, Inc. Integrated MS/xD Controller (rev 01)

instead my EEE-BOX which also feature a card reader is using a USB based adapter (although internal) which can be used as boot device.

AS

[Archie]

Well, my BIOS did not support booting from the card reader but I was able to boot using the USB adapter and the boot speed and reaction time was also fast and acceptable.

Is your card reader not attached to a USB port in the PC?

If not, how is it attached?

Thanks.

BTW ......  congrats on getting it working  

On a Sony VAIO laptop.

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lspci -v | grep 'Card Reader'
09:03.2 Mass storage controller: Texas Instruments 5-in-1 Multimedia Card Reader (SD/MMC/MS/MS PRO/xD)
Thank you, coco for the idea.

AS and Just18, thanks for the assistance and the info. I definitely learned something useful on this exercise.

Peace and much respect,
Archie