On 05.04.2022 10:45, Roger Pau Monné wrote: > On Thu, Mar 31, 2022 at 11:44:10AM +0200, Jan Beulich wrote: >> GrUB2 can be told to leave the screen in the graphics mode it has been >> using (or any other one), via "set gfxpayload=keep" (or suitable >> variants thereof). In this case we can avoid doing another mode switch >> ourselves. This in particular avoids possibly setting the screen to a >> less desirable mode: On one of my test systems the set of modes >> reported available by the VESA BIOS depends on whether the interposed >> KVM switch has that machine set as the active one. If it's not active, >> only modes up to 1024x768 get reported, while when active 1280x1024 >> modes are also included. For things to always work with an explicitly >> specified mode (via the "vga=" option), that mode therefore needs be a >> 1024x768 one. >> >> For some reason this only works for me with "multiboot2" (and >> "module2"); "multiboot" (and "module") still forces the screen into text >> mode, despite my reading of the sources suggesting otherwise. >> >> For starters I'm limiting this to graphics modes; I do think this ought >> to also work for text modes, but >> - I can't tell whether GrUB2 can set any text mode other than 80x25 >> (I've only found plain "text" to be valid as a "gfxpayload" setting), >> - I'm uncertain whether supporting that is worth it, since I'm uncertain >> how many people would be running their systems/screens in text mode, >> - I'd like to limit the amount of code added to the realmode trampoline. >> >> For starters I'm also limiting mode information retrieval to raw BIOS >> accesses. This will allow things to work (in principle) also with other >> boot environments where a graphics mode can be left in place. The >> downside is that this then still is dependent upon switching back to >> real mode, so retrieving the needed information from multiboot info is >> likely going to be desirable down the road. >> >> Signed-off-by: Jan Beulich <jbeul...@suse.com> > > Acked-by: Roger Pau Monné <roger....@citrix.com>
May I ask for an ack or otherwise for the changelog entry, please? Thanks, Jan
