[Qemu-devel] [PATCH V2 0/2] Fix bug in nios2 and m68k semihosting

[Qemu-devel] [PATCH V2 0/2] Fix bug in nios2 and m68k semihosting

[Sandra Loosemore]

I noticed recently that the exit semihosting call on nios2 was
ignoring its parameter and always returning status 0 instead.  It
turns out the handler was retrieving the value of the wrong register.
Since the nios2 semihosting implementation was basically
cut-and-pasted from that for m68k, I checked m68k also and it had the
same bug.  This set of patches fixes both of them.

There are no changes to the actual patches from V1, only more
informative commit messages with links to the respective semihosting
protocol documents in newlib.

Sandra Loosemore (2):
  target/nios2: Fix bug in semihosted exit handling
  target/m68k: Fix bug in semihosted exit handling

 target/m68k/m68k-semi.c   | 4 ++--
 target/nios2/nios2-semi.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

-- 
2.8.1

[Qemu-devel] [PATCH V2 1/2] target/nios2: Fix bug in semihosted exit handling

[Sandra Loosemore]

This patch fixes a bug that caused semihosted exit to always return
status 0; it was incorrectly using the value of register R_ARG0 (which
contains the HOSTED_EXIT request number) instead of register R_ARG1.

Note that per the newlib documentation for the nios2 semihosting protocol

https://www.sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;a=blob;f=libgloss/nios2/nios2-semi.txt;h=ded3a093c03dbae84cb95b4cd45bc3e0d751eda2;hb=HEAD

for the HOSTED_EXIT syscall the parameter is passed directly in the register
instead of in a parameter block pointed to by the register.

Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
---
 target/nios2/nios2-semi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/nios2/nios2-semi.c b/target/nios2/nios2-semi.c
index d7a80dd..06c0861 100644
--- a/target/nios2/nios2-semi.c
+++ b/target/nios2/nios2-semi.c
@@ -215,8 +215,8 @@ void do_nios2_semihosting(CPUNios2State *env)
     args = env->regs[R_ARG1];
     switch (nr) {
     case HOSTED_EXIT:
-        gdb_exit(env, env->regs[R_ARG0]);
-        exit(env->regs[R_ARG0]);
+        gdb_exit(env, env->regs[R_ARG1]);
+        exit(env->regs[R_ARG1]);
     case HOSTED_OPEN:
         GET_ARG(0);
         GET_ARG(1);
-- 
2.8.1

[Qemu-devel] [PATCH V2 2/2] target/m68k: Fix bug in semihosted exit handling

[Sandra Loosemore]

This patch fixes a bug that caused semihosted exit to always return
status 0; it was incorrectly using the value of D0 (which
contains the HOSTED_EXIT request number) instead of D1.

Note that per the newlib documentation for the m68k semihosting protocol

https://www.sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;a=blob;f=libgloss/m68k/m68k-semi.txt;h=50520c15292aa7edf7eef28e09fd9202ce75b153;hb=HEAD

for the HOSTED_EXIT syscall the parameter is passed directly in the register
instead of in a parameter block pointed to by the register.

Signed-off-by: Sandra Loosemore <sandra@codesourcery.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
---
 target/m68k/m68k-semi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/m68k/m68k-semi.c b/target/m68k/m68k-semi.c
index 8e5fbfc..f189c92 100644
--- a/target/m68k/m68k-semi.c
+++ b/target/m68k/m68k-semi.c
@@ -194,8 +194,8 @@ void do_m68k_semihosting(CPUM68KState *env, int nr)
     args = env->dregs[1];
     switch (nr) {
     case HOSTED_EXIT:
-        gdb_exit(env, env->dregs[0]);
-        exit(env->dregs[0]);
+        gdb_exit(env, env->dregs[1]);
+        exit(env->dregs[1]);
     case HOSTED_OPEN:
         GET_ARG(0);
         GET_ARG(1);
-- 
2.8.1