| Message ID | CALicx6sr=OXYAdSS-RXPCjSp4f_yLQyw6jJsQ2KyhgQ9fRtXag@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/07/13 12:56, Vijay Kilari wrote: > On Fri, Jul 12, 2013 at 5:17 PM, Thomas Petazzoni > <thomas.petazzoni@free-electrons.com> wrote: >> Dear Vijay Kilari, >> >> On Fri, 12 Jul 2013 17:09:12 +0530, Vijay Kilari wrote: >> >>>> Ben Dooks has a separate branch on top of this base branch for >>>> big-endian support, that adds atags compat code to convert the ATAGs >>>> data from LE to BE. See the baserock/311/be/atags branch in >>>> git://git.baserock.org/delta/linux. Or >>>> http://git.baserock.org/cgi-bin/cgit.cgi/delta/linux.git/log/?h=baserock/311/be/atags. >>> >>> ARM VE TC2 board, enabling CONFIG_THUMB2_KERNEL failed to boot in BE mode >>> It hangs at very early stage of boot >> >> Yeah, the Thumb2 code is not supported by Ben Dooks patches, it's part >> of the TODO-list. I think Ben said he would probably not have much time >> to work on this. I might be able to spare some time on this, so just >> let me know if I should start working on this. If I remember correctly, >> it's mainly the fixup_pv_table code that needed some Thumb2/BE love. > > In fact, I tried with below changes.. still it fails > > diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S > index 2de1114..7df64c7 100644 > --- a/arch/arm/kernel/head.S > +++ b/arch/arm/kernel/head.S > @@ -592,8 +592,14 @@ __fixup_a_pv_table: > b 2f > 1: add r7, r3 > ldrh ip, [r7, #2] > +#ifdef CONFIG_CPU_ENDIAN_BE8 > + rev ip, ip > +#endif Do you need a rev16 here? I think you may have tried reversing the full 32 bits here instead of just the 16bits of instruction that was loaded. > and ip, 0x8f00 > orr ip, r6 @ mask in offset bits 31-24 > +#ifdef CONFIG_CPU_ENDIAN_BE8 > + rev ip, ip > +#endif > strh ip, [r7, #2] > 2: cmp r4, r5 > ldrcc r7, [r4], #4 @ use branch for delay slot > >> >> Will, is getting Thumb2 working a requirement to get the BE support >> merged, or can we for now make the BE option depends on !THUMB2_KERNEL ? >> >> Thanks! >> >> Thomas >> -- >> Thomas Petazzoni, Free Electrons >> Kernel, drivers, real-time and embedded Linux >> development, consulting, training and support. >> http://free-electrons.com
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 2de1114..7df64c7 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -592,8 +592,14 @@ __fixup_a_pv_table: b 2f 1: add r7, r3 ldrh ip, [r7, #2] +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev ip, ip +#endif and ip, 0x8f00 orr ip, r6 @ mask in offset bits 31-24 +#ifdef CONFIG_CPU_ENDIAN_BE8 + rev ip, ip +#endif strh ip, [r7, #2] 2: cmp r4, r5 ldrcc r7, [r4], #4 @ use branch for delay slot