Luca Falavigna <[EMAIL PROTECTED]> writes: > Luca Falavigna ha scritto: >> Eric W. Biederman ha scritto: >> >>>>Anyway I believe you also want to look at include/linux/tty.h >>>>at the screen_info structure. I believe that is where >>>>all of that information is passed. >> >> I noticed. Maybe if we fill struct x86_linux_param_header with some values >> obtained from struct screen_info, we should be able to "score that mid-court >> prayer" ;) >> > I tried to implement a new ioctl command in fb_ioctl() in order to retrieve > and > store screen_info variables into struct x86_linux_param_header, but I got the > same result: no messages shown in console, as I supposed. Hmm. very odd. Sounds very much like an implementation problem.
> After that I looked at video.S, especially an interesting label called > "video": > > # This is the main entry point called by setup.S > # %ds *must* be pointing to the bootsector > video: pushw %ds # We use different segments > pushw %ds # FS contains original DS > popw %fs > [...] > #ifdef CONFIG_VIDEO_SELECT > movw %fs:(0x01fa), %ax # User selected video mode > cmpw $ASK_VGA, %ax # Bring up the menu > jz vid2 > [...] > > Video mode is stored (by bootloader, actually) at offset 0x01fa from a given > boot sector, which should be located at physical address DEF_SETUPSEG > (0x9020). > Feel free to correct me if I'm wrong. That is the default address, it can actually move quite a bit. > If we could store current video mode before executing reboot_code_buffer, > probably setup() function would take care of anything else. So we could > implement a function (or an assembly stub) in machine_kexec which does this > job. > I think this is the best (and safest) solution. That is why we have sys_kexec_load(). With a working ioctl (or other way to query the information) we just need to populate screen_info from x86-linux-setup.c in /sbin/kexec. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
