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arm: cpu: handle BE32 user-mode as BE 

endian with address manipulations on subword accesses (to give the
illusion of BE). But user-mode cannot tell the difference and is
already implemented as straight BE. So handle the difference in the
endianess query, where USER mode is BE and system is not.

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Crosthwaite 2016-03-04 11:30:19 +00:00 committed by Peter Maydell
parent ed50ff7875
commit b2e62d9a7b
1 changed files with 16 additions and 1 deletions
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17
target-arm/cpu.h
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@ -1915,7 +1915,22 @@ static inline bool arm_cpu_data_is_big_endian(CPUARMState *env)
/* In 32bit endianness is determined by looking at CPSR's E bit */
if (!is_a64(env)) {
return (env->uncached_cpsr & CPSR_E) ? 1 : 0;
return
#ifdef CONFIG_USER_ONLY
/* In system mode, BE32 is modelled in line with the
* architecture (as word-invariant big-endianness), where loads
* and stores are done little endian but from addresses which
* are adjusted by XORing with the appropriate constant. So the
* endianness to use for the raw data access is not affected by
* SCTLR.B.
* In user mode, however, we model BE32 as byte-invariant
* big-endianness (because user-only code cannot tell the
* difference), and so we need to use a data access endianness
* that depends on SCTLR.B.
*/
arm_sctlr_b(env) ||
#endif
((env->uncached_cpsr & CPSR_E) ? 1 : 0);
}
cur_el = arm_current_el(env);