[Qemu-devel] [PATCH V3] Fix : [Bug 887516] [NEW] VFP support reported for the PXA270

[Qemu-devel] [PATCH V3] Fix : [Bug 887516] [NEW] VFP support reported for the PXA270

[Benoît Canet]

A VFP was detected for pxa270 causing an "Illegal instruction"
exception.
The eglibc was not receiving the right AT_HWCAP from elfloader.c.

In this version (Andreas and Peter comments)
rename GET_FEATURE macro to SET_HWCAP
remove wrong VFP_FP16 to VFPv3-D16 mapping
remove unconditional ARM_HWCAP_ARM_FPA capability
update elfloader.c arm capability list
add missing arm capability mappings
add a feature sync reminder in target-arm/cpu.h

Benoît Canet (2):
  arm-linux-user: fix elfload.c's AT_HWCAP to reflect cpu features.
  target-arm: remind to keep arm features in sync with
    linux-user/elfload.c

 linux-user/elfload.c |   38 ++++++++++++++++++++++++++++++++++----
 target-arm/cpu.h     |    2 ++
 2 files changed, 36 insertions(+), 4 deletions(-)

-- 
1.7.5.4

[Qemu-devel] [PATCH 1/2] arm-linux-user: fix elfload.c's AT_HWCAP to reflect cpu features.

[Benoît Canet]

The cpu capabilities passed by the elf loader in AT_HWCAP where
a constant.
Make AT_HWCAP reflect the emulated cpu features in order to give
correct clues to eglibc.

Fix :  [Bug 887516] [NEW] VFP support reported for the PXA270

Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
---
 linux-user/elfload.c |   38 ++++++++++++++++++++++++++++++++++----
 1 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index a413976..3e1654c 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -330,6 +330,10 @@ enum
     ARM_HWCAP_ARM_NEON      = 1 << 11,
     ARM_HWCAP_ARM_VFPv3     = 1 << 12,
     ARM_HWCAP_ARM_VFPv3D16  = 1 << 13,
+    ARM_HWCAP_ARM_TLS       = 1 << 14,
+    ARM_HWCAP_ARM_VFPv4     = 1 << 15,
+    ARM_HWCAP_ARM_IDIVA     = 1 << 16,
+    ARM_HWCAP_ARM_IDIVT     = 1 << 17,
 };
 
 #define TARGET_HAS_GUEST_VALIDATE_BASE
@@ -375,10 +379,36 @@ bool guest_validate_base(unsigned long guest_base)
     return 1; /* All good */
 }
 
-#define ELF_HWCAP (ARM_HWCAP_ARM_SWP | ARM_HWCAP_ARM_HALF               \
-                   | ARM_HWCAP_ARM_THUMB | ARM_HWCAP_ARM_FAST_MULT      \
-                   | ARM_HWCAP_ARM_FPA | ARM_HWCAP_ARM_VFP              \
-                   | ARM_HWCAP_ARM_NEON | ARM_HWCAP_ARM_VFPv3 )
+
+#define ELF_HWCAP get_elf_hwcap()
+
+static uint32_t get_elf_hwcap(void)
+{
+    CPUState *e = thread_env;
+    uint32_t hwcaps = 0;
+
+    hwcaps |= ARM_HWCAP_ARM_SWP;
+    hwcaps |= ARM_HWCAP_ARM_HALF;
+    hwcaps |= ARM_HWCAP_ARM_THUMB;
+    hwcaps |= ARM_HWCAP_ARM_FAST_MULT;
+
+    /* probe for the extra features */
+#define SET_HWCAP(feat, hwcap) \
+    do {if (arm_feature(e, feat)) { hwcaps |= hwcap; } } while (0)
+    SET_HWCAP(ARM_FEATURE_VFP, ARM_HWCAP_ARM_VFP);
+    SET_HWCAP(ARM_FEATURE_IWMMXT, ARM_HWCAP_ARM_IWMMXT);
+    SET_HWCAP(ARM_FEATURE_THUMB2EE, ARM_HWCAP_ARM_THUMBEE);
+    SET_HWCAP(ARM_FEATURE_NEON, ARM_HWCAP_ARM_NEON);
+    SET_HWCAP(ARM_FEATURE_VFP3, ARM_HWCAP_ARM_VFPv3);
+    SET_HWCAP(ARM_FEATURE_V5, ARM_HWCAP_ARM_EDSP);
+    SET_HWCAP(ARM_FEATURE_V6K, ARM_HWCAP_ARM_TLS);
+    SET_HWCAP(ARM_FEATURE_VFP4, ARM_HWCAP_ARM_VFPv4);
+    SET_HWCAP(ARM_FEATURE_ARM_DIV, ARM_HWCAP_ARM_IDIVA);
+    SET_HWCAP(ARM_FEATURE_THUMB_DIV, ARM_HWCAP_ARM_IDIVT);
+#undef SET_HWCAP
+
+    return hwcaps;
+}
 
 #endif
 
-- 
1.7.5.4

Re: [Qemu-devel] [PATCH 1/2] arm-linux-user: fix elfload.c's AT_HWCAP to reflect cpu features.

[Peter Maydell]

2011/11/9 Benoît Canet <benoit.canet@gmail.com>:
> +    SET_HWCAP(ARM_FEATURE_V5, ARM_HWCAP_ARM_EDSP);

You've dropped the comment I suggested to go with this one.

-- PMM

[Qemu-devel] [PATCH 2/2] target-arm: remind to keep arm features in sync with linux-user/elfload.c

[Benoît Canet]

Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
---
 target-arm/cpu.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index c4d742f..e51bc8a 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -353,6 +353,8 @@ enum arm_cpu_mode {
 #define ARM_IWMMXT_wCGR2	10
 #define ARM_IWMMXT_wCGR3	11
 
+/* remember to update linux-user/elfload.c get_elf_hwcap arm's
+ * version when adding a feature */
 enum arm_features {
     ARM_FEATURE_VFP,
     ARM_FEATURE_AUXCR,  /* ARM1026 Auxiliary control register.  */
-- 
1.7.5.4

Re: [Qemu-devel] [PATCH 2/2] target-arm: remind to keep arm features in sync with linux-user/elfload.c

[Peter Maydell]

2011/11/9 Benoît Canet <benoit.canet@gmail.com>:
> +/* remember to update linux-user/elfload.c get_elf_hwcap arm's
> + * version when adding a feature */

/* If adding a feature bit which corresponds to a Linux ELF
 * HWCAP bit, remember to update the feature-bit-to-hwcap
 * mapping in linux-user/elfload.c:get_elf_hwcap().
 */

-- PMM