[Qemu-devel] [PATCH V3] Target-arm: Add the Cortex-M4 CPU

["Aurelio C. Remonda" <aurelioremonda@gmail.com>]

This patch adds the Cortex-M4 CPU. The M4 is basically the same as the M3,
the main differences being the DSP instructions and an optional FPU.
Created an ARM_FEATURE_THUMB_DSP to be added to any non-M thumb2-compatible
CPU that uses DSP instructions, and manually added it to the M4 in its initfn.

Signed-off-by: Aurelio C. Remonda <aurelioremonda@gmail.com>
---
* Changes in V3: Add the ARM_FEATURE_THUMB_DSP in a separate patch and create 
just the CPU init on this one.
 target-arm/cpu.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 4a888ab..4950897 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -783,6 +783,21 @@ static void cortex_m3_initfn(Object *obj)
     cpu->midr = 0x410fc231;
 }
 
+static void cortex_m4_initfn(Object *obj)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    set_feature(&cpu->env, ARM_FEATURE_V7);
+    set_feature(&cpu->env, ARM_FEATURE_M);
+    set_feature(&cpu->env, ARM_FEATURE_THUMB_DSP);
+    cpu->midr = 0x410fc240;
+    /*main id register CPUID bit assignments
+    Bits    NAME        Function
+    [31:24] IMPLEMENTER Indicates implementor: 0x41 = ARM
+    [23:20] VARIANT     Indicates processor revision: 0x0 = Revision 0
+    [19:16] (Constant)  Reads as 0xF
+    [15:4]  PARTNO      Indicates part number: 0xC24 = Cortex-M4
+    [3:0]   REVISION    Indicates patch release: 0x0 = Patch 0.*/
+}
 static void arm_v7m_class_init(ObjectClass *oc, void *data)
 {
     CPUClass *cc = CPU_CLASS(oc);
@@ -1185,6 +1200,8 @@ static const ARMCPUInfo arm_cpus[] = {
     { .name = "arm11mpcore", .initfn = arm11mpcore_initfn },
     { .name = "cortex-m3",   .initfn = cortex_m3_initfn,
                              .class_init = arm_v7m_class_init },
+    { .name = "cortex-m4",   .initfn = cortex_m4_initfn,
+                             .class_init = arm_v7m_class_init },
     { .name = "cortex-a8",   .initfn = cortex_a8_initfn },
     { .name = "cortex-a9",   .initfn = cortex_a9_initfn },
     { .name = "cortex-a15",  .initfn = cortex_a15_initfn },
-- 
1.9.1