Hi Albert,
On Tue, 21 Oct 2014 15:54:51 +0200 Albert ARIBAUD <albert.u.b...@aribaud.net> wrote: > Hi Georges, > > On Mon, 20 Oct 2014 23:08:30 +0200, Georges Savoundararadj > <savou...@gmail.com> wrote: > > > Hi Albert, > > > > Le 15/10/2014 00:11, Albert ARIBAUD a ecrit : > > > 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 ecrit : > > >>> 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, > > > > I am currently trying to implement solution 1. only for ARM1176 and > > ARMV7 but I wonder > > if this work worth the effort just for one CPU feature. > > Do you expect more CPU feature like HAS_VBAR coming in the future? > > > > I add the following lines in arch/arm/Kconfig: > > config HAS_VBAR > > bool > > > > config ARM1176 > > bool > > select HAS_VBAR > > > > config ARMV7 > > bool > > select HAS_VBAR > > > > config SYS_CPU > > default "arm1176" if ARM1176 > > default "armv7" if ARMV7 > > > > Then, in the same file, under each "config TARGET_<board>", I add > > "select ARM1176" or "select ARMV7". > > Also, I delete the Kconfig entries "config SYS_CPU" in all Kconfig of > > *all* boards that use ARM1176 and ARMV7. > > > > Actually, I find the change quite big. What do you think about this > > implementation? > > Should I continue in this direction? > > This looks like the right way to me (even if ideally I would prefer > that SYS_CPU be deduced from the SYS_SOC defined in the boards' Kconfig > files rather than added to them). > > Hopefully you can devise a sed, awk o perl script to do the change > without too much manual effort? > > Incidentally, this raises a question which Masahiro can probably > answer. In arch/arm/Kconfig, every ARM board is referred to twice: > > - once in a "config TARGET_<board>" block; > > - once in a "source board[/<maker>]/<board>/Kconfig directive. > > Would it be possible to move each "TARGET_<board>" block from > arch/arm/Kconfig to the corresponding board[/<maker>]/<board>/Kconfig > and only keep the "source" directives in arch/arm/Kconfig? I think it is impossible. The first one appears in "config choice" .. "endchoice" to select an appropriate board/platform. > (and then, I'd *really* like a way to source all ARM-based boards in a > few lines, e.g. source /board/*/Kconfig + source board/*/*/Kconfig) > > It would be nice if all Kconfig settings for a given board were found > in the board's Kconfig. I have no idea to achieve this. Best Regards Masahiro Yamada _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
