> On Apr 28, 2023, at 9:45 PM, Elliott Mitchell <ehem+open...@m5p.com> wrote: > > On Thu, Apr 27, 2023 at 11:21:28AM +0200, Thibaut wrote: >> >>> Le 27 avr. 2023 à 02:11, Elliott Mitchell <ehem+open...@m5p.com> a écrit : >>> >>> On Thu, Apr 27, 2023 at 12:50:52AM +0200, Stefan Lippers-Hollmann wrote: >>>> On 2023-04-19, Elliott Mitchell wrote: >>>>> Direct Rendering Manager is mainly for running X (possibly Wayland >>>>> too). As OpenWRT is meant for networking devices, there is no need >>>>> for the support to be present. >>>> >>>> That is only partially true, the Linux kernel is making a strong push >>>> away from deprecated (FB_*) graphics drivers to DRM based ones, with >>>> kernel based mode setting this is getting more (any) attention for >>>> console support as well. Even without getting anywhere near X/ Wayland, >>>> there is more than just a 80x25 tty on real hardware (and even VMs). >>> >>> Real x86 hardware often has the capability to use a serial port as >>> console. The conventional UEFI implementation fully supports this use >>> case. I can well believe a number of manufacturers disabling the >>> functionality though. >>> >>> VMs *can* have more than a 80x25 tty. By the time you're getting to 4 >>> or more VMs you should be thinking about disabling the functionality due >>> to the heavy overhead (unless the OS in the VM doesn't support serial >>> consoles). >> >> You seem to assume that x86 is only/mainly run on VMs. >> That is not necessarily the case, and I see no reason to degrade device >> support that way. > > Okay, as already stated there are at least two solutions to this. > > 1> Turn most functionality into modules and include support for runtime > loading of kernel modules. > > 2> Create more kernel variants for OpenWRT/x86. > > >> Would you mind documenting the measurable gains from your changes, so we >> have some metric to assess their relevance? >> > > I had suspected as much, but fully disabling ISA DMA didn't directly > have much impact (less than 4195 byte reduction). I was already guessing > most of the gain was CONFIG_ISA=n, but hoped purging ISA DMA might > squeeze out a bit more. > > Removing AGP shrunk vmlinux.bin by 4KB. Since the kernel is a multiple > of page size, this means a reduction of 1-8191 bytes. This though may > have translated into a larger impact when CONFIG_DRM was set to no. > > Setting CONFIG_DRM=n resulted in a vmlinux.bin delta of -2203648 bytes. > Not quite a 10% reduction in kernel runtime size, but close. Here we > have a major impact on kernel size. > > Removing USB support is certainly inappropriate for a desktop build, but > appropriate for something using a serial console (some types of VM). > That has a delta of -2117632 bytes.
I occasionally use the USB pass-thru with memory sticks to install or recover an VM. -Philip _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel