Hi, On 8 September 2015 at 16:46, Heiko St?bner <heiko at sntech.de> wrote: > > Hi Andy, > > Am Dienstag, 8. September 2015, 20:43:07 schrieb Andy Yan: > > rockchip platform have a protocol to pass the the kernel > > reboot mode to bootloader by some special registers when > > system reboot.By this way the bootloader can take different > > action according to the different kernel reboot mode, for > > example, command "reboot loader" will reboot the board to > > rockusb mode, this is a very convenient way to get the board > > to download mode. > > > > Signed-off-by: Andy Yan <andy.yan at rock-chips.com> > > [...] > > > @@ -0,0 +1,22 @@ > > +#ifndef __MACH_ROCKCHIP_LOADER_H > > +#define __MACH_ROCKCHIP_LOADER_H > > + > > +/*high 24 bits is tag, low 8 bits is type*/ > > +#define SYS_LOADER_REBOOT_FLAG 0x5242C300 > > + > > +enum { > > + BOOT_NORMAL = 0, /* normal boot */ > > + BOOT_LOADER, /* enter loader rockusb mode */ > > + BOOT_MASKROM, /* enter maskrom rockusb mode (not support now) */ > > + BOOT_RECOVER, /* enter recover */ > > + BOOT_NORECOVER, /* do not enter recover */ > > + BOOT_SECONDOS, /* boot second OS (not support now)*/ > > + BOOT_WIPEDATA, /* enter recover and wipe data. */ > > + BOOT_WIPEALL, /* enter recover and wipe all data. */ > > + BOOT_CHECKIMG, /* check firmware img with backup part*/ > > + BOOT_FASTBOOT, /* enter fast boot mode */ > > + BOOT_SECUREBOOT_DISABLE, > > + BOOT_CHARGING, /* enter charge mode */ > > + BOOT_MAX /* MAX VALID BOOT TYPE.*/ > > +}; > > +#endif > > These flags rely on code in the bootloader to actually handle the target > action. Nowadays this is uboot, but still a rockchip-specific fork. And we're > actively moving away from that, with the recent rk3288 addition to mainline > uboot. > > So unless you convince uboot people that the _underlying special > functionality_ behind these flags should be part of uboot, I don't think this > is going to fly. > > > In a way this is similar to gpu kernel code talking to proprietary userspace > libs - these are also not eligible for the kernel. (meaning stuff like the > mali kernel driver not being allowed). I don't want to comment on what Linux does or does not want. But I can see this sort of feature being useful for devs at least. So long as it is defined in a way that is not Rockchip-specific (and the above enum looks pretty reasonable on that front, I think it makes sense. Of course it's a bit odd to target a downstream U-Boot with a Linux feature. But hopefully Rockchip's U-Boot support and development will move to mainline with time. > > [...] > > > +static int rockchip_reboot_notify(struct notifier_block *this, > > + unsigned long mode, void *cmd) > > +{ > > + u32 flag; > > + > > + rockchip_get_reboot_flag(cmd, &flag); > > + regmap_write(regmap, flag_reg, flag); > > + > > + return NOTIFY_DONE; > > +} > > + > > +static struct notifier_block rockchip_reboot_handler = { > > + .notifier_call = rockchip_reboot_notify, > > + .priority = 150, > > +}; > > the restart handlers are meant to really only restart the system, not to > execute some actions before the restart happens. > > See https://lkml.org/lkml/2015/6/3/707 for a similar case. > > > Heiko Regards, Simon