[U-Boot] [PATCH v2 3/4] api: FreeBSD: flush cache before starting loader/kernel
Emmanuel Vadot
manu at bidouilliste.com
Tue Jan 17 21:45:44 CET 2017
On Tue, 17 Jan 2017 21:13:51 +0100
Alexander Graf <agraf at suse.de> wrote:
>
>
> On 17/01/2017 16:50, Emmanuel Vadot wrote:
> > From: Warner Losh <imp at freebsd.org>
> >
> > FreeBSD loader(8) just loaded code to some random location that may
> > contain stale icache entries.
> > FreeBSD Kernel needs the icache and dcache flushed.
> > Before running either one of them, flush the icache and dcache.
> >
> > Signed-off-by: Emmanuel Vadot <manu at bidouilliste.com>
>
> Is there any downside to doing the flush always? I would prefer to not
> conditionalize it on CONFIG_FREEBSD.
I don't think there is any downside.
> > ---
> > api/api.c | 5 +++++
> > cmd/boot.c | 5 +++++
> > cmd/elf.c | 8 +++++++-
> > 3 files changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/api/api.c b/api/api.c
> > index 8a1433af78..cc25deca09 100644
> > --- a/api/api.c
> > +++ b/api/api.c
> > @@ -290,6 +290,11 @@ static int API_dev_close(va_list ap)
> > if (!err)
> > di->state = DEV_STA_CLOSED;
> >
> > +#ifdef CONFIG_FREEBSD
> > + flush_dcache_all();
> > + invalidate_icache_all();
> > +#endif
> > +
> > return err;
> > }
> >
> > diff --git a/cmd/boot.c b/cmd/boot.c
> > index 72f2cf362d..a1a91fbf0a 100644
> > --- a/cmd/boot.c
> > +++ b/cmd/boot.c
> > @@ -19,6 +19,11 @@ __attribute__((weak))
> > unsigned long do_go_exec(ulong (*entry)(int, char * const []), int argc,
> > char * const argv[])
> > {
> > +#ifdef CONFIG_FREEBSD
> > + flush_dcache_all();
> > + invalidate_icache_all();
> > +#endif
> > +
> > return entry (argc, argv);
> > }
> >
> > diff --git a/cmd/elf.c b/cmd/elf.c
> > index 5190cc6c0f..b2827fa042 100644
> > --- a/cmd/elf.c
> > +++ b/cmd/elf.c
> > @@ -109,6 +109,7 @@ static unsigned long do_bootelf_exec(ulong (*entry)(int, char * const[]),
> > {
> > unsigned long ret;
> >
> > +#ifndef CONFIG_FREEBSD
> > /*
> > * QNX images require the data cache is disabled.
> > * Data cache is already flushed, so just turn it off.
> > @@ -116,15 +117,20 @@ static unsigned long do_bootelf_exec(ulong (*entry)(int, char * const[]),
> > int dcache = dcache_status();
> > if (dcache)
> > dcache_disable();
>
> Can FreeBSD boot with dcache disabled? Is there some way we can
> determine what payload we have from the elf header?
>
>
> Alex
FreeBSD can boot with dcache disabled (our loader and kernel can)
I'm not sure I get your other question, sorry.
--
Emmanuel Vadot <manu at bidouilliste.com> <manu at freebsd.org>
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