Re-partitioning; Adding swap partition; Using GPT partitions
#10
Quote:A normal GPT with the recommended partition array (plus the protective MBR) runs from LBA0 through to LBA 33 (and is repeated at the end of the disk). It is not a problem to have the first partition at LBA 64.
it's a bare minimum - 1 block goes to the Protective MBR (LBA 0), 1block for the GPT Header (LBA 1) and in case of 512 byte blocks - 32 blocks go for the Partition Array. normally, utilities initializing GPT disks allocate larger space for avoiding "no entries for number of partitions you wanted" situations.
the alignment recommendation (it's 1 MB, not 2, I was wrong) is for efficiency purposes, again "only" a recommendation, but every normal utility respects it. it's both relared to RAID and flash based storages efficient operations.

Quote:Frankly I'm not sure who your comment about dd is aimed at. The only use of dd in the thread so far is to copy the firmware from eMMC to SD and the GPT is created *after* the dd.
i mentioned it because in the Arwen's recipe, he dd-s first 128 KB (256 KBlocks) of eMMC onto an SD card. but that chunk contains GPT structures! doesn't it? as I know, all the distributions, except armbian, use the Rockchip scheme, that in turn makes use of the GPT scheme. I was talking about this case - it's wrong in many ways, it won't even create the Back up parts of GPT tables. in addition to duplicating unique GUIDs.

2 arwen, just saw you response, i am using android tablet and i hate it! the "keyboard" is made by sadists, it's unusable.
i understood, that you dded for copying uboot pieces. i just thought, that copying gpt present on emmc, will make (s)fdisk think about modifying the existing gpt rather than creating new one. but that existing is wrong
since i use armbian on my pine boards, i probably am wrong about the layout of non armbian distributions for pine.

and yes, about a proper installation, i wrote that too a couple of weeks ago, maybe someone noticed. i am not a linux guy, so I can't try myself in it. but that thing would be very good to have. i don't agree, that it's arm difference though. nothing special, x86 starts its execution at the predefined address aw well, that platform just managed to agree on always having flash chip from which bios runs, starting it all. this mess with uboot pieces being hardcoded at places in the user areas of not so "firmware" storages is mostly due to overlooking on the OS side, linux, in this case  lack of development force, other reasons. should it get enough attention, the only normal place for these pieces are either (in)famous SPI NOR chip, pretty fatty on pine products or, shoul rockchip be not this lazy, the boot areas of eMMC, specifically made for this purpose, leaving all the collisions with user data. then creating a modern GPT laid out disk on user disks would be free of this clumsy stuff.
ANT - my hobby OS for x86 and ARM.


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RE: Re-partitioning; Adding swap partition; Using GPT partitions - by z4v4l - 12-04-2019, 05:50 PM

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