Hi Georges, On Tue, 14 Oct 2014 22:02:00 +0200, Georges Savoundararadj <savou...@gmail.com> wrote:
> Hi Albert, > > Hi Masahiro, (putting Masahiro in Cc: just in case) > As my issue is related to Kconfig, I would like you to give me your > opinions. > > > Le 11/10/2014 12:47, Albert ARIBAUD a écrit : > > Hi Georges, > > > > On Sat, 27 Sep 2014 21:48:10 +0200, Georges Savoundararadj > > <savou...@gmail.com> wrote: > > > >> This commit relocates the exception vectors. > >> As ARM1176 and ARMv7 have the security extensions, it uses VBAR. For > >> the other ARM processors, it copies the relocated exception vectors to > >> the correct address: 0x00000000 or 0xFFFF0000. > >> > >> Signed-off-by: Georges Savoundararadj <savou...@gmail.com> > >> Cc: Albert Aribaud <albert.u.b...@aribaud.net> > >> Cc: Tom Warren <twar...@nvidia.com> > >> > >> --- > >> This patch needs some tests because it impacts many boards. I have > >> tested it with my raspberry pi in the two cases: using VBAR and > >> using the copied exception vectors. > >> > >> Changes in v2: > >> - Relocate exception vectors also on processors which do not support > >> security extensions > >> - Reword the commit message > >> > >> arch/arm/cpu/armv7/start.S | 6 ------ > >> arch/arm/lib/relocate.S | 30 ++++++++++++++++++++++++++++++ > >> 2 files changed, 30 insertions(+), 6 deletions(-) > >> > >> diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S > >> index fedd7c8..fdc05b9 100644 > >> --- a/arch/arm/cpu/armv7/start.S > >> +++ b/arch/arm/cpu/armv7/start.S > >> @@ -81,12 +81,6 @@ ENTRY(c_runtime_cpu_setup) > >> mcr p15, 0, r0, c7, c10, 4 @ DSB > >> mcr p15, 0, r0, c7, c5, 4 @ ISB > >> #endif > >> -/* > >> - * Move vector table > >> - */ > >> - /* Set vector address in CP15 VBAR register */ > >> - ldr r0, =_start > >> - mcr p15, 0, r0, c12, c0, 0 @Set VBAR > >> > >> bx lr > >> > >> diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S > >> index 8035251..88a478e 100644 > >> --- a/arch/arm/lib/relocate.S > >> +++ b/arch/arm/lib/relocate.S > >> @@ -6,6 +6,8 @@ > >> * SPDX-License-Identifier: GPL-2.0+ > >> */ > >> > >> +#include <asm-offsets.h> > >> +#include <config.h> > >> #include <linux/linkage.h> > >> > >> /* > >> @@ -52,6 +54,34 @@ fixnext: > >> cmp r2, r3 > >> blo fixloop > >> > >> + /* > >> + * Relocate the exception vectors > >> + */ > >> +#if (defined(CONFIG_ARM1176) || defined(CONFIG_ARMV7)) > > I would prefer a single CONFIG_HAS_VBAR symbol defined through > > Kconfig. > 1) > Actually, there is no Kconfig entry such as "config ARM1176" nor "config > ARMV7" in U-Boot, > unlike in Linux (arch/arm/mm/Kconfig). > > If there were such entries, we would simply do like the following (in > arch/arm/Kconfig): > > config HAS_VBAR > bool > > config ARM1176 > select HAS_VBAR > > config ARMV7 > select HAS_VBAR > > Should we go in this direction? > It is the cleanest way to use Kconfig but it requires some work in order > to convert all > "#define CONFIG_<cpu>" into Kconfig entries. > > 2) > Otherwise, we can insert a "select HAS_VBAR" in all boards that have a > ARM1176 or a ARMv7 > processor in arch/arm/Kconfig. It is not logical but this is what has > been done with the Kconfig > entry ARM64. And, it does not require much change. > > 3) > The last thing we can do is as follows: > > config HAS_VBAR > bool > depends on SYS_CPU = "arm1176" || SYS_CPU = "armv7" > default y > > CONFIG_HAS_VBAR will be defined if SYS_CPU are arm1176 or armv7. It does > not require much > change as well but, I think, it is bad code. > > What do you think is the best way to introduce CONFIG_HAS_VBAR symbol? > (1, 2 or 3) I believe you have already sorted the options in order of decreasing 'quality' -- 1 being the best option, and 3 being the worst... Indeed option 1 would be the best and cleanest, and it could possibly open the way for other per-CPU options. We could try and limit the effort to converting only ARM1176 and ARMV7 and leaving other CONFIG_<cpu> #define'd until some later point in the future, but experience shows that such half-hearted attempts are never completed. Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
