[v3] Add nanoMIPS support to QEMU

[Qemu-devel] [PATCH v3 29/40] target/mips: Adjust set_hflags_for_handler() for nanoMIPS

Posted by Stefan Markovic 7 years, 6 months ago

From: James Hogan <james.hogan@mips.com>

We shouldn't clear M16 mode when entering an interrupt on nanoMIPS,
otherwise we'll start interpreting the code as normal MIPS code.

Signed-off-by: James Hogan <james.hogan@mips.com>
Signed-off-by: Yongbok Kim <yongbok.kim@mips.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Stefan Markovic <smarkovic@wavecomp.com>
---
 target/mips/helper.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/target/mips/helper.c b/target/mips/helper.c
index fb47018..e5fc981 100644
--- a/target/mips/helper.c
+++ b/target/mips/helper.c
@@ -671,6 +671,9 @@ target_ulong exception_resume_pc (CPUMIPSState *env)
 #if !defined(CONFIG_USER_ONLY)
 static void set_hflags_for_handler (CPUMIPSState *env)
 {
+    if (env->insn_flags & ISA_NANOMIPS32) {
+        return;
+    }
     /* Exception handlers are entered in 32-bit mode.  */
     env->hflags &= ~(MIPS_HFLAG_M16);
     /* ...except that microMIPS lets you choose.  */
-- 
2.7.4

Re: [Qemu-devel] [PATCH v3 29/40] target/mips: Adjust set_hflags_for_handler() for nanoMIPS

Posted by Richard Henderson 7 years, 6 months ago

On 07/19/2018 05:55 AM, Stefan Markovic wrote:
> From: James Hogan <james.hogan@mips.com>
> 
> We shouldn't clear M16 mode when entering an interrupt on nanoMIPS,
> otherwise we'll start interpreting the code as normal MIPS code.
> 
> Signed-off-by: James Hogan <james.hogan@mips.com>
> Signed-off-by: Yongbok Kim <yongbok.kim@mips.com>
> Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
> Signed-off-by: Stefan Markovic <smarkovic@wavecomp.com>
> ---
>  target/mips/helper.c | 3 +++
>  1 file changed, 3 insertions(+)

See my comments for 28/40.