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target-arm: Wire up HLT 0xf000 as the A64 semihosting instruction

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For the A64 instruction set, the semihosting call instruction
is 'HLT 0xf000'. Wire this up to call do_arm_semihosting()
if semihosting is enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Christopher Covington <christopher.covington@linaro.org>
Tested-by: Christopher Covington <cov@codeaurora.org>
Message-id: 1439483745-28752-10-git-send-email-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2015-09-07 10:39:28 +01:00
parent 7446d35e1d
commit 8012c84ff9
5 changed files with 34 additions and 2 deletions
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3
linux-user/main.c
View File

@ -1052,6 +1052,9 @@ void cpu_loop(CPUARMState *env)
queue_signal(env, info.si_signo, &info);
}
break;
case EXCP_SEMIHOST:
env->xregs[0] = do_arm_semihosting(env);
break;
default:
fprintf(stderr, "qemu: unhandled CPU exception 0x%x - aborting\n",
trapnr);

1
target-arm/cpu.h
View File

@ -56,6 +56,7 @@
#define EXCP_SMC 13 /* Secure Monitor Call */
#define EXCP_VIRQ 14
#define EXCP_VFIQ 15
#define EXCP_SEMIHOST 16 /* semihosting call (A64 only) */
#define ARMV7M_EXCP_RESET 1
#define ARMV7M_EXCP_NMI 2

6
target-arm/helper-a64.c
View File

@ -514,6 +514,12 @@ void aarch64_cpu_do_interrupt(CPUState *cs)
case EXCP_VFIQ:
addr += 0x100;
break;
case EXCP_SEMIHOST:
qemu_log_mask(CPU_LOG_INT,
"...handling as semihosting call 0x%" PRIx64 "\n",
env->xregs[0]);
env->xregs[0] = do_arm_semihosting(env);
return;
default:
cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
}

2
target-arm/internals.h
View File

@ -36,6 +36,7 @@ static inline bool excp_is_internal(int excp)
|| excp == EXCP_HALTED
|| excp == EXCP_EXCEPTION_EXIT
|| excp == EXCP_KERNEL_TRAP
|| excp == EXCP_SEMIHOST
|| excp == EXCP_STREX;
}
@ -58,6 +59,7 @@ static const char * const excnames[] = {
[EXCP_SMC] = "Secure Monitor Call",
[EXCP_VIRQ] = "Virtual IRQ",
[EXCP_VFIQ] = "Virtual FIQ",
[EXCP_SEMIHOST] = "Semihosting call",
};
static inline void arm_log_exception(int idx)

22
target-arm/translate-a64.c
View File

@ -30,6 +30,7 @@
#include "internals.h"
#include "qemu/host-utils.h"
#include "exec/semihost.h"
#include "exec/gen-icount.h"
#include "exec/helper-proto.h"
@ -1553,9 +1554,28 @@ static void disas_exc(DisasContext *s, uint32_t insn)
unallocated_encoding(s);
break;
}
/* HLT */
/* HLT. This has two purposes.
* Architecturally, it is an external halting debug instruction.
* Since QEMU doesn't implement external debug, we treat this as
* it is required for halting debug disabled: it will UNDEF.
* Secondly, "HLT 0xf000" is the A64 semihosting syscall instruction.
*/
if (semihosting_enabled() && imm16 == 0xf000) {
#ifndef CONFIG_USER_ONLY
/* In system mode, don't allow userspace access to semihosting,
* to provide some semblance of security (and for consistency
* with our 32-bit semihosting).
*/
if (s->current_el == 0) {
unsupported_encoding(s, insn);
break;
}
#endif
gen_exception_internal_insn(s, 0, EXCP_SEMIHOST);
} else {
unsupported_encoding(s, insn);
}
break;
case 5:
if (op2_ll < 1 || op2_ll > 3) {
unallocated_encoding(s);