semihosting: Implement SYS_ISERROR

Part of Semihosting for AArch32 and AArch64 Release 2.0

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210107170717.2098982-10-keithp@keithp.com>
Message-Id: <20210108224256.2321-21-alex.bennee@linaro.org>

diff --git a/hw/semihosting/arm-compat-semi.c b/hw/semihosting/arm-compat-semi.c
index a631904..23c6e3e 100644 (file)
--- a/hw/semihosting/arm-compat-semi.c
+++ b/hw/semihosting/arm-compat-semi.c
@@ -59,6 +59,7 @@
 #define TARGET_SYS_WRITE       0x05
 #define TARGET_SYS_READ        0x06
 #define TARGET_SYS_READC       0x07
+#define TARGET_SYS_ISERROR     0x08
 #define TARGET_SYS_ISTTY       0x09
 #define TARGET_SYS_SEEK        0x0a
 #define TARGET_SYS_FLEN        0x0c
@@ -967,6 +968,9 @@ target_ulong do_common_semihosting(CPUState *cs)
         return guestfd_fns[gf->type].readfn(cs, gf, arg1, len);
     case TARGET_SYS_READC:
         return qemu_semihosting_console_inc(cs->env_ptr);
+    case TARGET_SYS_ISERROR:
+        GET_ARG(0);
+        return (target_long) arg0 < 0 ? 1 : 0;
     case TARGET_SYS_ISTTY:
         GET_ARG(0);