Uclinux-2008r1-rc8 (bf561) to VDSP5 transplantation (in): __EBSS_L1

At the end of the Setup_arch function, there is this statement:

/* Copy atomic sequences to their fixed location, and sanity check that
These locations are the ones, we advertise to userspace. */
memcpy (void *) Fixed_code_start, &fixed_code_start,
Fixed_code_end-fixed_code_start);
BUG_ON ((char *) &sigreturn_stub-(char *) &fixed_code_start
!= Sigreturn_stub-fixed_code_start);
BUG_ON ((char *) &ATOMIC_XCHG32-(char *) &fixed_code_start
!= Atomic_xchg32-fixed_code_start);
BUG_ON ((char *) &ATOMIC_CAS32-(char *) &fixed_code_start
!= Atomic_cas32-fixed_code_start);
BUG_ON ((char *) &ATOMIC_ADD32-(char *) &fixed_code_start
!= Atomic_add32-fixed_code_start);
BUG_ON ((char *) &ATOMIC_SUB32-(char *) &fixed_code_start
!= Atomic_sub32-fixed_code_start);
BUG_ON ((char *) &atomic_ior32-(char *) &fixed_code_start
!= Atomic_ior32-fixed_code_start);
BUG_ON ((char *) &ATOMIC_AND32-(char *) &fixed_code_start
!= Atomic_and32-fixed_code_start);
BUG_ON ((char *) &atomic_xor32-(char *) &fixed_code_start
!= Atomic_xor32-fixed_code_start);
BUG_ON ((char *) &safe_user_instruction-(char *) &fixed_code_start
!= Safe_user_instruction-fixed_code_start);

Here, several definitions of Fixed_code_start are in include/asm/fixed_code.h:

///* This file defines the fixed addresses where userspace programs can find
//　　 atomic code sequences. */
//
#define FIXED_CODE_START　　　 0x400
//
#define SIGRETURN_STUB　　　　　 0x400
//
#define ATOMIC_SEQS_START　　 0x410
//
#define ATOMIC_XCHG32　　　　　　 0x410
#define ATOMIC_CAS32　　　　　　　 0x420
#define ATOMIC_ADD32　　　　　　　 0x430
#define ATOMIC_SUB32　　　　　　　 0x440
#define ATOMIC_IOR32　　　　　　　 0x450
#define ATOMIC_AND32　　　　　　　 0x460
#define ATOMIC_XOR32　　　　　　　 0x470
//
#define ATOMIC_SEQS_END　　　　 0x480
//
#define SAFE_USER_INSTRUCTION　　 0x480
//
#define FIXED_CODE_END　　　　　 0x490
//

And Fixed_code_start is a symbol defined in ARCH/BLACKFIN/KERNEL/FIXED_CODE.S. There is a description in the FIXED_CODE.S:

/*
　* This file contains sequences of code that will be copied to a
　* fixed location, defined in <asm/atomic_seq.h>. The interrupt
　* handlers ensure that these sequences appear to be atomic when
　* executed from userspace.
　* These are aligned to 16 bytes, so that we have some space to replace
　* these sequences with something else (e.g. kernel traps if we ever do
　* BF561 SMP).
　*/