[U-Boot] [PATCH v2] ARM: Disable "DISCARD" for secure section if CONFIG_ARMV7_SECURE_BASE isn't defined

[Dongsheng Wang]

Thanks, Albert.

Regards,
-Dongsheng

> -----Original Message-----
> From: Albert ARIBAUD [mailto:albert.u.boot at aribaud.net]
> Sent: Saturday, January 30, 2016 12:21 AM
> To: Tom Rini <trini at konsulko.com>
> Cc: Dongsheng Wang <dongsheng.wang at nxp.com>;
> alison.wang at freescale.com; jan.kiszka at siemens.com; oss at buserror.net; u-
> boot at lists.denx.de; twarren at nvidia.com; ijc at hellion.org.uk;
> yorksun at freescale.com
> Subject: Re: [U-Boot] [PATCH v2] ARM: Disable "DISCARD" for secure section if
> CONFIG_ARMV7_SECURE_BASE isn't defined
> 
> Hello Tom,
> 
> On Tue, 19 Jan 2016 10:57:11 -0500, Tom Rini <trini at konsulko.com> wrote:
> > On Mon, Jan 18, 2016 at 11:02:40AM +0800, Dongsheng Wang wrote:
> >
> > > From: Wang Dongsheng <dongsheng.wang at nxp.com>
> > >
> > > "DISCARD" will remove ._secure.text relocate, but PSCI framework has
> > > already used some absolute address those need to relocate.
> > >
> > > Use readelf -t -r u-boot show us:
> > > .__secure_start		addr: 601408e4
> > > .__secure_end		addr: 60141460
> > >
> > > 60141140  00000017 R_ARM_RELATIVE
> > > 46	_secure_monitor:
> > > 47	#ifdef CONFIG_ARMV7_PSCI
> > > 48      ldr     r5, =_psci_vectors
> > >
> > > 60141194  00000017 R_ARM_RELATIVE
> > > 6014119c  00000017 R_ARM_RELATIVE
> > > 601411a4  00000017 R_ARM_RELATIVE
> > > 601411ac  00000017 R_ARM_RELATIVE
> > > 64	_psci_table:
> > > 66	.word	psci_cpu_suspend
> > > ...
> > > 72	.word	psci_migrate
> > >
> > > 60141344  00000017 R_ARM_RELATIVE
> > > 6014145c  00000017 R_ARM_RELATIVE
> > > 202	ldr     r5, =psci_text_end
> > >
> > > Solutions:
> > > 1. Change absolute address to RelAdr.
> > >    Based on LDR (immediate, ARM), we only have 4K offset to jump.
> > > Now PSCI code size is close to 4K size that is LDR limit jump size,
> > > so even if the LDR is based on the current instruction address,
> > > there is also have a risk for RelAdr. If we use two jump steps I
> > > think we can fix this issue, but looks too hack, so give up this way.
> > >
> > > 2. Enable "DISCARD" only for CONFIG_ARMV7_SECURE_BASE has defined.
> > >    If CONFIG_ARMV7_SECURE_BASE is defined in platform, all of secure
> > > will in the BASE address that is absolute.
> > >
> > > Signed-off-by: Wang Dongsheng <dongsheng.wang at nxp.com>
> > >
> > > diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds index
> > > d48a905..e148ab7 100644
> >
> > Reviewed-by: Tom Rini <trini at konsulko.com>
> >
> > --
> > Tom
> 
> Applied to u-boot-arm/master, thanks!
> 
> Amicalement,
> --
> Albert.