On 07/06/2012 01:35 AM, Albert ARIBAUD albert.u.boot@aribaud.net (by way of Albert ARIBAUD wrote:
Hi Zhong Hongbo,
On Thu, 05 Jul 2012 19:53:46 +0800, Zhong Hongbo bocui107@gmail.com wrote:
Hi Albert,
Could you applied the patch to the arm tree?
Thanks, hongbo On 07/03/2012 07:46 AM, Zhong Hongbo wrote:
From: Zhong Hongbo bocui107@gmail.com
In the spl booting step, When __bss_start is equal to __bss_end__, The loop will clear all the things in CPU space. If there are have the same address for this symbol, To skip the clear bss section.
Signed-off-by: Hongbo Zhong bocui107@gmail.com
arch/arm/cpu/armv7/start.S | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S index 76ccef1..c72f337 100644 --- a/arch/arm/cpu/armv7/start.S +++ b/arch/arm/cpu/armv7/start.S @@ -258,6 +258,8 @@ clear_bss: /* No relocation for SPL */ ldr r0, =__bss_start ldr r1, =__bss_end__
- cmp r0, r1
- beq skip_clbss
#else ldr r0, _bss_start_ofs ldr r1, _bss_end_ofs @@ -271,6 +273,7 @@ clbss_l:str r2, [r0] /* clear loop... */ add r0, r0, #4 cmp r0, r1 bne clbss_l +skip_clbss:
Clearly the loop was wrong in that it should implement a "for (r0 = start; r0 < end; r0++)" but actually implements a "for (r0 = start; r0 != end; r0++)".
Yes， My new patch have do this.
I'd rather the loop be fixed to match the intended implementation rather than worked around. Please rewrite your patch to turn:
Ok, I just found the issue have found in other arm platfor 2011 yeas, the detail information as following:
commit 8f1da53508c78789ebeea98a92a3f55c3f84dc5d Author: Christian Riesch christian.riesch@omicron.at Date: Wed Nov 30 22:27:37 2011 +0000
arm, arm926ejs: Fix clear bss loop for zero length bss
This patch fixes the clear bss loop for bss sections that have zero length, i.e., where __bss_start == __bss_end__.
Signed-off-by: Christian Riesch christian.riesch@omicron.at Cc: Albert Aribaud albert.u.boot@aribaud.net
diff --git a/arch/arm/cpu/arm926ejs/start.S b/arch/arm/cpu/arm926ejs/start.S index 339c5ed..bb4d00b 100644 --- a/arch/arm/cpu/arm926ejs/start.S +++ b/arch/arm/cpu/arm926ejs/start.S @@ -301,10 +301,12 @@ clear_bss: #endif mov r2, #0x00000000 /* clear */
-clbss_l:str r2, [r0] /* clear loop... */ +clbss_l:cmp r0, r1 /* clear loop... */ + bhs clbss_e /* if reached end of bss, exit */ + str r2, [r0] add r0, r0, #4 - cmp r0, r1 - bne clbss_l + b clbss_l +clbss_e:
clbss_l:str r2, [r0] /* clear loop...*/ add r0, r0, #4 cmp r0, r1 bne clbss_l
Into something like
clbss_l:cmp r0, r1 blo clbss_d str r2, [r0] /* clear loop...*/ add r0, r0, #4 b clbss_l clbss_d:
Also, as Andreas points out, make sure the same fix is applied to all ARM start.S files which need it.
Ok，
Thanks, hongbo
Thanks in advance.
Amicalement,