1 files changed, 19 insertions, 15 deletions

diff --git a/arch/blackfin/mach-common/head.S b/arch/blackfin/mach-common/head.S
index 698d4c05947e..f826f6b9f917 100644
--- a/arch/blackfin/mach-common/head.S
+++ b/arch/blackfin/mach-common/head.S
@@ -30,8 +30,6 @@ ENTRY(__init_clear_bss)
         rts;
 ENDPROC(__init_clear_bss)
 
-#define INITIAL_STACK   (L1_SCRATCH_START + L1_SCRATCH_LENGTH - 12)
-
 ENTRY(__start)
         /* R0: argument of command line string, passed from uboot, save it */
         R7 = R0;
@@ -126,30 +124,30 @@ ENTRY(__start)
          * below
          */
         GET_PDA(p0, r0);
-        r7 = [p0 + PDA_RETX];
+        r6 = [p0 + PDA_RETX];
         p1.l = _init_saved_retx;
         p1.h = _init_saved_retx;
-        [p1] = r7;
+        [p1] = r6;
 
-        r7 = [p0 + PDA_DCPLB];
+        r6 = [p0 + PDA_DCPLB];
         p1.l = _init_saved_dcplb_fault_addr;
         p1.h = _init_saved_dcplb_fault_addr;
-        [p1] = r7;
+        [p1] = r6;
 
-        r7 = [p0 + PDA_ICPLB];
+        r6 = [p0 + PDA_ICPLB];
         p1.l = _init_saved_icplb_fault_addr;
         p1.h = _init_saved_icplb_fault_addr;
-        [p1] = r7;
+        [p1] = r6;
 
-        r7 = [p0 + PDA_SEQSTAT];
+        r6 = [p0 + PDA_SEQSTAT];
         p1.l = _init_saved_seqstat;
         p1.h = _init_saved_seqstat;
-        [p1] = r7;
+        [p1] = r6;
 #endif
 
         /* Initialize stack pointer */
-        sp.l = lo(INITIAL_STACK);
-        sp.h = hi(INITIAL_STACK);
+        sp.l = _init_thread_union;
+        sp.h = _init_thread_union;
         fp = sp;
         usp = sp;
 
@@ -189,7 +187,15 @@ ENTRY(__start)
         /* Put The Code for PLL Programming and SDRAM Programming in L1 ISRAM */
         call _bfin_relocate_l1_mem;
 #ifdef CONFIG_BFIN_KERNEL_CLOCK
+        /* Only use on-chip scratch space for stack when absolutely required
+         * to avoid Anomaly 05000227 ... we know the init_clocks() func only
+         * uses L1 text and stack space and no other memory region.
+         */
+# define KERNEL_CLOCK_STACK (L1_SCRATCH_START + L1_SCRATCH_LENGTH - 12)
+        sp.l = lo(KERNEL_CLOCK_STACK);
+        sp.h = hi(KERNEL_CLOCK_STACK);
         call _init_clocks;
+        sp = usp;       /* usp hasnt been touched, so restore from there */
 #endif
 
         /* This section keeps the processor in supervisor mode
@@ -243,9 +249,7 @@ ENTRY(_real_start)
         call _cmdline_init;
 
         /* Load the current thread pointer and stack */
-        sp.l = _init_thread_union;
-        sp.h = _init_thread_union;
-        p1 = THREAD_SIZE (z);
+        p1 = THREAD_SIZE + 4 (z);       /* +4 is for reti loading */
         sp = sp + p1;
         usp = sp;
         fp = sp;