[U-Boot] [PATCH] powerpc/mpc85xx: Use GOT when loading IVORs post-relocation

[York Sun <yorksun@freescale.com>]

Shaohui,

Thanks for confirmation. Please reply with your Test-by or Acked-by signature.
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York

On 04/23/2015 08:01 PM, Xie Shaohui-B21989 wrote:
> Tested on T4240QDS_NAND and T4240QDS_SDCARD, the hang issue fixed.
> Thanks!
> 
> Best Regards, 
> Shaohui Xie
> 
>> -----Original Message-----
>> From: Wood Scott-B07421
>> Sent: Friday, April 24, 2015 9:02 AM
>> To: u-boot at lists.denx.de; Sun York-R58495
>> Cc: Wood Scott-B07421; Alexander Graf; Xie Shaohui-B21989
>> Subject: [PATCH] powerpc/mpc85xx: Use GOT when loading IVORs post-
>> relocation
>>
>> Commit 96d2bb952bb ("powerpc/mpc85xx: Don't relocate exception vectors")
>> simplified IVOR initialization a bit too much, failing to use the post-
>> relocation offset.  This doesn't cause a problem with normal NOR boot, in
>> which both the pre-relocation and post-relocation addresses are 64 KiB
>> aligned.  However, if TEXT_BASE is only 4 KiB aligned, such as for
>> NAND/SD/etc. boot on some targets, as well as the QEMU target, the post-
>> relocation address will not be the same in the lower 16 bits, as
>> reserve_uboot() ensures that the relocation address is always 64 KiB
>> aligned even if the pre-relocation address was not.
>>
>> Use the GOT to get the proper post-relocation offsets.
>>
>> Fixes: 96d2bb952bb ("powerpc/mpc85xx: Don't relocate exception vectors")
>> Signed-off-by: Scott Wood <scottwood@freescale.com>
>> Cc: Alexander Graf <agraf@suse.de>
>> Cc: Shaohui Xie <Shaohui.Xie@freescale.com>
>> ---
>>  arch/powerpc/cpu/mpc85xx/start.S | 35 ++++++++++++++++++++--------------
>> -
>>  1 file changed, 20 insertions(+), 15 deletions(-)
>>
>> diff --git a/arch/powerpc/cpu/mpc85xx/start.S
>> b/arch/powerpc/cpu/mpc85xx/start.S
>> index 28f04ee..e61d8e0 100644
>> --- a/arch/powerpc/cpu/mpc85xx/start.S
>> +++ b/arch/powerpc/cpu/mpc85xx/start.S
>> @@ -1664,41 +1664,46 @@ clear_bss:
>>  	 */
>>  	.globl	trap_init
>>  trap_init:
>> +	mflr	r11
>> +	bl	_GLOBAL_OFFSET_TABLE_-4
>> +	mflr	r12
>> +
>>  	/* Update IVORs as per relocation */
>>  	mtspr	IVPR,r3
>>
>> -	li	r4,CriticalInput at l
>> +	lwz	r4,CriticalInput at got(r12)
>>  	mtspr	IVOR0,r4	/* 0: Critical input */
>> -	li	r4,MachineCheck at l
>> +	lwz	r4,MachineCheck at got(r12)
>>  	mtspr	IVOR1,r4	/* 1: Machine check */
>> -	li	r4,DataStorage at l
>> +	lwz	r4,DataStorage at got(r12)
>>  	mtspr	IVOR2,r4	/* 2: Data storage */
>> -	li	r4,InstStorage at l
>> +	lwz	r4,InstStorage at got(r12)
>>  	mtspr	IVOR3,r4	/* 3: Instruction storage */
>> -	li	r4,ExtInterrupt at l
>> +	lwz	r4,ExtInterrupt at got(r12)
>>  	mtspr	IVOR4,r4	/* 4: External interrupt */
>> -	li	r4,Alignment at l
>> +	lwz	r4,Alignment at got(r12)
>>  	mtspr	IVOR5,r4	/* 5: Alignment */
>> -	li	r4,ProgramCheck at l
>> +	lwz	r4,ProgramCheck at got(r12)
>>  	mtspr	IVOR6,r4	/* 6: Program check */
>> -	li	r4,FPUnavailable at l
>> +	lwz	r4,FPUnavailable at got(r12)
>>  	mtspr	IVOR7,r4	/* 7: floating point unavailable */
>> -	li	r4,SystemCall at l
>> +	lwz	r4,SystemCall at got(r12)
>>  	mtspr	IVOR8,r4	/* 8: System call */
>>  	/* 9: Auxiliary processor unavailable(unsupported) */
>> -	li	r4,Decrementer at l
>> +	lwz	r4,Decrementer at got(r12)
>>  	mtspr	IVOR10,r4	/* 10: Decrementer */
>> -	li	r4,IntervalTimer at l
>> +	lwz	r4,IntervalTimer at got(r12)
>>  	mtspr	IVOR11,r4	/* 11: Interval timer */
>> -	li	r4,WatchdogTimer at l
>> +	lwz	r4,WatchdogTimer at got(r12)
>>  	mtspr	IVOR12,r4	/* 12: Watchdog timer */
>> -	li	r4,DataTLBError at l
>> +	lwz	r4,DataTLBError at got(r12)
>>  	mtspr	IVOR13,r4	/* 13: Data TLB error */
>> -	li	r4,InstructionTLBError at l
>> +	lwz	r4,InstructionTLBError at got(r12)
>>  	mtspr	IVOR14,r4	/* 14: Instruction TLB error */
>> -	li	r4,DebugBreakpoint at l
>> +	lwz	r4,DebugBreakpoint at got(r12)
>>  	mtspr	IVOR15,r4	/* 15: Debug */
>>
>> +	mtlr	r11
>>  	blr
>>
>>  .globl unlock_ram_in_cache
>> --
>> 2.1.0
>