2015-04-14 20:07 GMT+02:00 Matt Porter <mpor...@konsulko.com>: > > On ARM v7M, the processor will return to ARM mode when executing > a blx instruction with bit 0 of the address == 0. Always set it > to 1 to stay in thumb mode. > > Signed-off-by: Matt Porter <mpor...@konsulko.com> > --- > common/cmd_boot.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/common/cmd_boot.c b/common/cmd_boot.c > index 8f2e070..20ce652 100644 > --- a/common/cmd_boot.c > +++ b/common/cmd_boot.c > @@ -38,6 +38,10 @@ static int do_go(cmd_tbl_t *cmdtp, int flag, int argc, > char * const argv[]) > * pass address parameter as argv[0] (aka command name), > * and all remaining args > */ > +#ifdef CONFIG_CPU_V7M > + /* For ARM V7M, set bit zero to stay in Thumb mode */ > + addr++; > +#endif > rc = do_go_exec ((void *)addr, argc - 1, argv + 1); > if (rc != 0) rcode = 1; > > -- > 2.1.0 > >
I think addr |= 1 would be better - there is always a possibility that kernel image has the zero bit already set (this is the case in my own Buildroot build setup I am using for STM32F4 builds). Anyways - keeping this bit set should be the responsibility of kernel image build process so such machine specific quirk can be kept out of the common code. /Kamil _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
