Stefano and Nicola, > Stefano, Nicola > >> On Wed, 2 Apr 2025, Nicola Vetrini wrote: >>> On 2025-03-28 07:43, Kwon, Gihwan wrote: >>>> Dear Xen Community, >>>> >>>> I hope this message finds you well. >>>> >>>> I have heard that there exists a minimal Xen configuration optimized >>>> for safety-critical products, particularly in automotive applications, >>>> with the code size reduced to approximately 50k SLOC. >>>> >>>> Could anyone provide guidance or point me to relevant resources >>>> regarding this minimal Xen configuration? Any insights or references >>>> would be greatly appreciated. >>>> >>>> Thank you in advance for your assistance. >>>> >>>> Best regards, >>>> Gihwan Kwon >>> >>> Hello, >>> >>> I am part of the team that provides static analysis for Xen, mainly >>> towards the objective to make Xen compliant with MISRA C guidelines. >>> As part of that effort, a minimal Xen configuration has been defined >>> (for Arm and x86_64) at [1], which is the one currently analyzed for >>> static analysis for each commit [2]. It starts from the default >>> configuration for the architecture (i.e., make defconfig) and then >>> turns on or off various Kconfig options, as specified by >>> EXTRA_XEN_CONFIG. >>> >>> @Stefano Stabellini (Cc'ed) is the main driving force behind the Xen >>> certification effort for automotive, therefore he's probably the best >>> person to approach to get more information on this matter. >> >> Thanks Nicola. In addition to what Nicola wrote, there is an outstanding >> activity to further reduce the code size by adding more kconfig options. >> There are a couple of patch series on the list right now to that effect. >> >> https://marc.info/?l=xen-devel&m=173745442831026 >> >> Last year we ran some experiments and for ARM we should be able to go >> below 35K LOC. The tools measuring LOC are very imprecise as they do >> not account for #ifdefs and kconfig options. So we switched to text >> binary size for measurements as it is more accurate. do not account for >> kconfig options and #ifdefs. Hence, we switch to using text size as >> size measurement for Xen. One of the figure was XXX. > > Thank you for sharing information regarding the current minimal config > and additional activities. I have reviewed the configuration applied to the > CI and have a question. > Currently, `CONFIG_SCHED_RTDS` is enabled instead of > `CONFIG_SCHED_CREDIT2` and `CONFIG_SCHED_CREDIT`. Is this because > ARINC653 scheduler cannot be used as default scheduler, as well as, rt > scheduler is smaller than credit2 or credit scheduler?
Please disregard my previous message. I have double checked that mentioned configurations are set 'n'. Therefore, `CONFIG_SCHED_NULL` and `CONFIG_SCHED_CREDIT2` is being set and used in the minimal xen configuration. > > - Gihwan > > - Gihwan
