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Date: Fri, 25 Jun 2010 17:44:10 +0200
From: Christophe LYON <christophe.lyon@st.com>
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Subject: [Qemu-devel] [PATCH] ARM: semi-hosting support for stderr
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To: qemu-devel@nongnu.org

Hello,

I propose this small patch so that ARM semi-hosting handles stderr as 
expected when linking with Newlib/libgloss.

diff --git a/arm-semi.c b/arm-semi.c
index 9549e6c..6874036 100644
--- a/arm-semi.c
+++ b/arm-semi.c
@@ -211,8 +211,11 @@ uint32_t do_arm_semihosting(CPUState *env)
          if (strcmp(s, ":tt") == 0) {
              if (ARG(1) < 4)
                  return STDIN_FILENO;
-            else
+            else if (ARG(1) == 4)
                  return STDOUT_FILENO;
+           else
+             return STDERR_FILENO; /* See newlib/libgloss
+                                      implementation.  */
          }
          if (use_gdb_syscalls()) {
              gdb_do_syscall(arm_semi_cb, "open,%s,%x,1a4", ARG(0),


Christophe