[Nexthop] Address NVMe block size mismatch#781
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ctikku-nexthop wants to merge 4 commits intofacebook:mainfrom
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[Nexthop] Address NVMe block size mismatch#781ctikku-nexthop wants to merge 4 commits intofacebook:mainfrom
ctikku-nexthop wants to merge 4 commits intofacebook:mainfrom
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This was referenced Jan 15, 2026
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Summary: **Pre-submission checklist** - [x] I've ran the linters locally and fixed lint errors related to the files I modified in this PR. You can install the linters by running `pip install -r requirements-dev.txt && pre-commit install` - [x] `pre-commit run` Including needed libraries python3.12 and nl3 libraries needed for the fboss binaries in the distro image. Found through using ldd on an installed binary and corrected. Based behind #781 that's waiting on review for more distro image adjustments, so will include those changes as well. The commit in question should be last in the list at 12871fe Pull Request resolved: #816 Test Plan: Tested on a minipack3 and loaded up the most recent fboss binaries: ``` [root@fboss103 fboss]# ldd bin/sai_test-sai_impl | grep python libpython3.12.so.1.0 => /lib64/libpython3.12.so.1.0 (0x00007f3970000000) [root@fboss103 fboss]# ldd bin/sai_test-sai_impl | grep found [root@fboss103 fboss]# ``` Reviewed By: kevin645 Differential Revision: D92423287 Pulled By: KevinYakar fbshipit-source-id: d6e73d59fcb510c32c9c55a76b1b2db376eac4cf
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@ctikku-nexthop has updated the pull request. You must reimport the pull request before landing. |
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Pre-submission checklist
pip install -r requirements-dev.txt && pre-commit installpre-commit runSummary
The NVMe controllers have the capability to define “block size” to different values (512, 4096,
etc). This works just fine as long as we read and write directly from/to the device.
However, when we pre-build a bootable image using kiwi-ng, we also create the Master
Boot Record (MBR) and GPT partition table etc. These are expected to be placed in
“known” locations on the NMVe device, MBR at block 0 and primary GPT at block 1.
What kiwi-ng generates is a raw dump of the disk image that is slapped on block 0
and contains everything necessary for the device.
The problem happens when the NVMe controller block size is “NOT” 512 bytes (say its
4096 byte) and we are trying to boot an kiwi-ng generated image that we placed on
the device. grub tries to locate the GPT partition at block 1, aka offset 4096 on the
device but kiwi-ng placed it at offset 512 and hence is unable to find a bootable device.
The fix is to match the block size that kiwi-ng and NVMe controller use are the same.
Test Plan