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1. scsi-disk: allow MODE SELECT block descriptor to set the block size Link:356c4c441eThe MODE SELECT command can contain an optional block descriptor that can be used to set the device block size. If the block descriptor is present then update the block size on the SCSI device accordingly. This allows CDROMs to be used with A/UX which requires a CDROM drive which is capable of switching from a 2048 byte sector size to a 512 byte sector size. 2. scsi-disk: ensure block size is non-zero and changes limited to bits 8-15 Link:55794c904dThe existing code assumes that the block size can be generated from p[1] << 8 in multiple places which ignores the top and bottom 8 bits. If the block size is allowed to be set to an arbitrary value then this causes a mismatch between the value written by the guest in the block descriptor and the value subsequently read back using READ CAPACITY causing the guest to generate requests that can crash QEMU. For now restrict block size changes to bits 8-15 and also ignore requests to set the block size to 0 which causes the SCSI emulation to crash in at least one place with a divide by zero error. 3. Disallow block sizes smaller than 512 [CVE-2023-42467] Link:7cfcc79b0aWe are doing things like nb_sectors /= (s->qdev.blocksize / BDRV_SECTOR_SIZE); in the code here (e.g. in scsi_disk_emulate_mode_sense()), so if the blocksize is smaller than BDRV_SECTOR_SIZE (=512), this crashes with a division by 0 exception. Thus disallow block sizes of 256 bytes to avoid this situation. (From OE-Core rev: e9af3d328db8a32c22bb0798fa8dbb749e3f607b) Signed-off-by: Poonam Jadhav <poonam.jadhav@kpit.com> Signed-off-by: Steve Sakoman <steve@sakoman.com>
Poky
Poky is an integration of various components to form a pre-packaged build system and development environment which is used as a development and validation tool by the Yocto Project. It features support for building customised embedded style device images and custom containers. There are reference demo images ranging from X11/GTK+ to Weston, commandline and more. The system supports cross-architecture application development using QEMU emulation and a standalone toolchain and SDK suitable for IDE integration.
Additional information on the specifics of hardware that Poky supports is available in README.hardware. Further hardware support can easily be added in the form of BSP layers which extend the systems capabilities in a modular way. Many layers are available and can be found through the layer index.
As an integration layer Poky consists of several upstream projects such as BitBake, OpenEmbedded-Core, Yocto documentation, the 'meta-yocto' layer which has configuration and hardware support components. These components are all part of the Yocto Project and OpenEmbedded ecosystems.
The Yocto Project has extensive documentation about the system including a reference manual which can be found at https://docs.yoctoproject.org/
OpenEmbedded is the build architecture used by Poky and the Yocto project. For information about OpenEmbedded, see the OpenEmbedded website.
Contribution Guidelines
The project works using a mailing list patch submission process. Patches should be sent to the mailing list for the repository the components originate from (see below). Throughout the Yocto Project, the README files in the component in question should detail where to send patches, who the maintainers are and where bugs should be reported.
A guide to submitting patches to OpenEmbedded is available at:
https://www.openembedded.org/wiki/How_to_submit_a_patch_to_OpenEmbedded
There is good documentation on how to write/format patches at:
https://www.openembedded.org/wiki/Commit_Patch_Message_Guidelines
Where to Send Patches
As Poky is an integration repository (built using a tool called combo-layer), patches against the various components should be sent to their respective upstreams:
OpenEmbedded-Core (files in meta/, meta-selftest/, meta-skeleton/, scripts/):
- Git repository: https://git.openembedded.org/openembedded-core/
- Mailing list: openembedded-core@lists.openembedded.org
BitBake (files in bitbake/):
- Git repository: https://git.openembedded.org/bitbake/
- Mailing list: bitbake-devel@lists.openembedded.org
Documentation (files in documentation/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/yocto-docs/
- Mailing list: docs@lists.yoctoproject.org
meta-yocto (files in meta-poky/, meta-yocto-bsp/):
- Git repository: https://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto
- Mailing list: poky@lists.yoctoproject.org
If in doubt, check the openembedded-core git repository for the content you intend to modify as most files are from there unless clearly one of the above categories. Before sending, be sure the patches apply cleanly to the current git repository branch in question.