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.mayd...@linaro.org> --- linux-user/main.c | 3 +++ target-arm/cpu.h | 1 + target-arm/helper-a64.c | 6 ++++++ target-arm/internals.h | 2 ++ target-arm/translate-a64.c | 14 ++++++++++++-- 5 files changed, 24 insertions(+), 2 deletions(-) diff --git a/linux-user/main.c b/linux-user/main.c index fdee981..56f452e 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -1054,6 +1054,9 @@ 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); diff --git a/target-arm/cpu.h b/target-arm/cpu.h index e067faa..fd91288 100644 --- a/target-arm/cpu.h +++ b/target-arm/cpu.h @@ -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 diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c index 08c95a3..02fc9b4 100644 --- a/target-arm/helper-a64.c +++ b/target-arm/helper-a64.c @@ -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); } diff --git a/target-arm/internals.h b/target-arm/internals.h index 924aff9..36a56aa 100644 --- a/target-arm/internals.h +++ b/target-arm/internals.h @@ -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) diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 689f2be..8810760 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -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" @@ -1553,8 +1554,17 @@ static void disas_exc(DisasContext *s, uint32_t insn) unallocated_encoding(s); break; } - /* HLT */ - unsupported_encoding(s, insn); + /* 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) { + gen_exception_internal_insn(s, 0, EXCP_SEMIHOST); + } else { + unsupported_encoding(s, insn); + } break; case 5: if (op2_ll < 1 || op2_ll > 3) { -- 1.9.1