> On 01/13/2017 10:36 AM, Alison Wang wrote: > >> On 01/13/2017 09:23 AM, Alison Wang wrote: > >>>>> Am 13.01.2017 um 08:50 schrieb Alison Wang <b18...@freescale.com>: > >>>>> > >>>>> For 64-bit kernel, there is a warning about x1-x3 nonzero in > >>>> violation > >>>>> of boot protocol. x3 should be reset to zero before jumping to > the > >>>>> kernel. > >>>>> > >>>>> This patch will adjust the parameters to transfer and make sure > x3 > >>>>> is zero. > >>>>> > >>>>> Signed-off-by: Alison Wang <alison.w...@nxp.com> > >>>> If x3 is part of the boot protocol, please treat it as function > >>>> argument rather than hard code it to 0. > >>>> > >>> [Alison Wang] I think x3 need to set to 0. Refer to the codes for > >>> the warning in kernel, > >>> > >>> if (boot_args[1] || boot_args[2] || boot_args[3]) { > >>> pr_err("WARNING: x1-x3 nonzero in violation of > >>> boot > >> protocol:\n" > >> "\tx1: %016llx\n\tx2: %016llx\n\tx3: %016llx\n" > >>> "This indicates a broken bootloader or > old > >> kernel\n", > >>> boot_args[1], boot_args[2], boot_args[3]); > >>> } > >> Yes, that merely means that the kernel doesn't take 3 arguments, it > >> takes 4. Today args[1..3] have to be 0, but I don't want to iron > that > >> out in u-boot code. > >> > >> So in pseudo-code, what we do today is we call > >> > >> entry(dt_addr, 0, 0); > >> > >> and instead we should be calling > >> > >> entry(dt_addr, 0, 0, 0); > >> > >> So in U-Boot code that means we should change the prototype for our > >> switch function from > >> > >> void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr, > >> u64 entry_point, u64 es_flag); > >> > >> to > >> > >> void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr, > >> u64 arg4, u64 entry_point, u64 es_flag); > >> > >> and adapt the macros accordingly to use x5/x6 instead of x4/5. > >> > > [Alison Wang] I understand your meaning. Actually, I thought that > method too. Well, my concern is that there are more changes. Not only > armv8_switch_to_el2 and armv8_switch_to_el1, all the places calling > them need to change too. It may cause more problems. With this concern, > I choose a simple way to fix this issue before. > > I think there'll be enough people testing Linux boot :), let's try to > fix it properly right away. > [Alison Wang] Ok, I will send v2 patch. Please help to review.
Thanks. Best Regards, Alison Wang _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot