Author Topic: Internal Memory  (Read 3297 times)

josephmanis

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Internal Memory
« on: January 10, 2010, 02:35:21 pm »
So, to the developers...

Why is it that dingux cannot access the internal memory.  What measures would need to be taken to make such a feature possible.  many thanks
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Chris23235

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  • Posts: 603
Re: Internal Memory
« Reply #1 on: January 10, 2010, 04:07:50 pm »
It would be necessary to implement the support into the linux kernel I think, but I also think booboo decided not to do that, cause Dingux corrupts SD cards on a regular basis and it wouldn't be wise to mess up the internal memory of the Dingoo. That was always my theory, why there is no support for the internal memory in Dingux.
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zear

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  • Posts: 2379
Re: Internal Memory
« Reply #2 on: January 10, 2010, 04:26:03 pm »
I think the answer is in the readme of dualboot:
Quote from: booboo
To write to NAND flash you must first erase the entire block, and each
block wears each time it is erased. For MLC (Multi-Level Cell) flash
chips the guaranteed minimum erase cycles are around 1000. That is not
much, and is usually not a problem because firmware and operating
systems do what is called "wear leveling". To make a long story short,
they put a translation layer that spreads writes to different blocks.
If you erase 1000 times a logical block, you will actually be erasing
1000 different physical blocks once each.
If I understand correctly, a "wear leveling" would have to be implemented in dingux in order to not kill the nand very quickly.
That's why we don't have NAND support in dingux. IMHO.
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darfgarf

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Re: Internal Memory
« Reply #3 on: January 10, 2010, 05:27:31 pm »
Quote from: Chris23235 on January 10, 2010, 04:07:50 pm
It would be necessary to implement the support into the linux kernel I think, but I also think booboo decided not to do that, cause Dingux corrupts SD cards on a regular basis and it wouldn't be wise to mess up the internal memory of the Dingoo. That was always my theory, why there is no support for the internal memory in Dingux.

pretty much just this

there's no problem with having it on an sd card anyways, apart from the corruption, but that won't change even if it does use the internal
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Chris23235

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  • Posts: 603
Re: Internal Memory
« Reply #4 on: January 10, 2010, 10:02:56 pm »
Quote from: zear on January 10, 2010, 04:26:03 pm
I think the answer is in the readme of dualboot:
Quote from: booboo
To write to NAND flash you must first erase the entire block, and each
block wears each time it is erased. For MLC (Multi-Level Cell) flash
chips the guaranteed minimum erase cycles are around 1000. That is not
much, and is usually not a problem because firmware and operating
systems do what is called "wear leveling". To make a long story short,
they put a translation layer that spreads writes to different blocks.
If you erase 1000 times a logical block, you will actually be erasing
1000 different physical blocks once each.
If I understand correctly, a "wear leveling" would have to be implemented in dingux in order to not kill the nand very quickly.
That's why we don't have NAND support in dingux. IMHO.

As far as I know, it has nothing to do with the NAND memory of the Dingoo. The internal 4GB aren't the NAND memory, the NAND is much smaller and is the place, where the boot routines are stored.
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darfgarf

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Re: Internal Memory
« Reply #5 on: January 11, 2010, 10:48:50 am »
Quote from: Chris23235 on January 10, 2010, 10:02:56 pm
As far as I know, it has nothing to do with the NAND memory of the Dingoo. The internal 4GB aren't the NAND memory, the NAND is much smaller and is the place, where the boot routines are stored.
that's correct, though it is probably some form of nand flash memory, like you find in a usb stick, hence people confusing the storage part of it, with the boot sectory type bit of it, i think it's both on the same physical chip, the dualboot installer just uses the first 64K of it(or whatever, no idea how much it is really)
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Lord Rocket

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Re: Internal Memory
« Reply #6 on: January 11, 2010, 07:38:51 pm »
What about read-only access?
That way we could use the flash memory for music and other files that don't need to be messed with.
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darfgarf

  • Guest
Re: Internal Memory
« Reply #7 on: January 11, 2010, 08:14:41 pm »
Quote from: Lord Rocket on January 11, 2010, 07:38:51 pm
What about read-only access?
That way we could use the flash memory for music and other files that don't need to be messed with.
i see no problem with it, but you'll need to find a dev who a)knows enough to get it working properly and b)has enough time/motivation to do it

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joyrider

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    • Willems Soft
Re: Internal Memory
« Reply #8 on: January 18, 2010, 06:18:40 pm »
i'm able to mount internal nand in dingux (as a raw device). you need to know the exact offset on the nand where the FAT32 partition starts and implement it in the nand driver in the kernel source not that hard, i have it working and can probably mount the internal nand soon. You also have to use ubifs to mount it, haven't bothered with that yet, i'm just trying to make an image with dd which i can write back, that's why i wanted raw access. it shows up as an mtd0 device. I tried a few things, but all my attempts on writing back the dumped nand failed already (although i only tried once using dd). and it seems i can't get the original os to boot anymore dingux is no problem but original os just does nothing even after succesfully using the unbricker tool (Unless it's something with my vmware).

If i get the original os going again i can probably try some more :)
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