On Thu, Jan 31, 2019 at 3:30 PM Bin Meng <bmeng...@gmail.com> wrote: > > On Thu, Jan 31, 2019 at 9:24 AM Simon Glass <s...@chromium.org> wrote: > > > > Hi, > > > > On Wed, 30 Jan 2019 at 12:03, Heinrich Schuchardt <xypron.g...@gmx.de> > > wrote: > > > > > > On 1/30/19 11:46 AM, Alexander Graf wrote: > > > > Our selftest will soon test the actual runtime reset function rather > > > > than > > > > the boot time one. For this, we need to ensure that the runtime version > > > > actually succeeds on x86 to keep our travis tests work. > > > > > > > > So this patch implements an x86 runtime reset function. It is missing > > > > shutdown functionality today, but OSs usually implement that via ACPI > > > > and this function does more than the stub from before, so it's at least > > > > an improvement. > > > > > > > > Eventually we will want to have full DM functionality in runtime > > > > services. > > > > But this fixes a travis failure and doesn't clutter the code too > > > > heavily, so > > > > we should pull it in without the amazing new RTS DM framework. > > > > > > > > Signed-off-by: Alexander Graf <ag...@suse.de> > > > > > > > > --- > > > > > > > > v2 -> v3: > > > > > > > > - support EFI_RESET_PLATFORM_SPECIFIC > > > > - reuse existing x86_sysreset_request() function > > > > > > The v2->v3 update does not answer the question if the reset is correctly > > > implemented. We would not want to call a function we do not trust. > > > > > > @Simon, Bin: > > > x86_sysreset_request() loosely resembles BOOT_CF9_SAFE in > > > native_machine_emergency_restart() in Linux arch/x86/kernel/reboot.c > > > which is tried before using the keyboard controller as last resort. > > > > > > u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E; > > > u8 cf9 = inb(0xcf9) & ~reboot_code; > > > outb(cf9|2, 0xcf9); /* Request hard reset */ > > > udelay(50); > > > /* Actually do the reset */ > > > outb(cf9|reboot_code, 0xcf9); > > > udelay(50); > > > > > > So the Kernel first switches bit 2 off and bit 1 on, waits, and then > > > switches bit 2 on, cf. > > > http://smackerelofopinion.blogspot.com/2011/02/resetting-pc-using-reset-control.html > > > > > > Shouldn't we do it the same way as the Kernel does it? > > > > I suspect so, but Bin is the expert. > > > > What U-Boot does is essentially the same as Linux but a simplified > version, because bit 2 is 0 any way. If it were 0, the system should
Sorry, a typo: If it were "1" > have been reset already then there is no chance to execute the reset > sequence at all. > > > As to this patch, it perpetuates the current EFI run-time approach in > > U-Boot so I'm not sure this is the right path. > > > Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
