Halfword memory accesses

testjig/production/arm_debug.cpp

@@ -296,6 +296,42 @@ bool ARMDebug::memLoadByte(uint32_t addr, uint8_t &data)
     return true;
 }
 
+bool ARMDebug::memStoreHalf(uint32_t addr, uint16_t data)
+{
+    if (!memWait())
+        return false;
+    if (!memWriteCSW(CSW_16BIT))
+        return false;
+    if (!apWrite(MEM_TAR, addr))
+        return false;
+
+    log(LOG_TRACE_MEM, "MEM Store [%08x] %04x", addr, data);
+
+    // Replicate across lanes
+    uint32_t word = data | (data << 16);
+
+    return apWrite(MEM_DRW, word);
+}
+
+bool ARMDebug::memLoadHalf(uint32_t addr, uint16_t &data)
+{
+    uint32_t word;
+    if (!memWait())
+        return false;
+    if (!memWriteCSW(CSW_16BIT))
+        return false;
+    if (!apWrite(MEM_TAR, addr))
+        return false;
+    if (!apRead(MEM_DRW, word))
+        return false;
+
+    // Select the proper lane
+    data = word >> ((addr & 2) << 3);
+
+    log(LOG_TRACE_MEM, "MEM Load  [%08x] %04x", addr, data);
+    return true;
+}
+
 bool ARMDebug::apWrite(unsigned addr, uint32_t data)
 {
     log(LOG_TRACE_AP, "AP  Write [%x] %08x", addr, data);

testjig/production/arm_debug.h

@@ -73,6 +73,10 @@ public:
     bool memStoreByte(uint32_t addr, uint8_t data);
     bool memLoadByte(uint32_t addr, uint8_t &data);
 
+    // Halfword (16-bit) load/store operations (AHB bus)
+    bool memStoreHalf(uint32_t addr, uint16_t data);
+    bool memLoadHalf(uint32_t addr, uint16_t &data);
+
     // Poll for an expected value
     bool memPoll(unsigned addr, uint32_t &data, uint32_t mask, uint32_t expected, unsigned retries = DEFAULT_RETRIES);
 

testjig/production/arm_kinetis_debug.cpp

@@ -139,7 +139,7 @@ bool ARMKinetisDebug::peripheralInit()
     if (!memStoreAndVerify(0x20000000, 0x76543210))
         return false;
 
-    // Test byte-wide writes
+    // Test byte-wide memory access
     uint32_t word;
     uint8_t byte;
     if (!memStoreByte(0x20000001, 0x55))
@@ -155,7 +155,26 @@ bool ARMKinetisDebug::peripheralInit()
     if (!memLoadByte(0x20000003, byte))
         return false;
     if (byte != 0x76) {
-        log(LOG_ERROR, "ARMKinetisDebug: Byte-wide AHB read seems broken! (Test byte = %08x)", byte);
+        log(LOG_ERROR, "ARMKinetisDebug: Byte-wide AHB read seems broken! (Test byte = %02x)", byte);
+        return false;
+    }
+
+    // Test halfword-wide memory access
+    uint16_t half;
+    if (!memStoreHalf(0x20000000, 0x5abc))
+        return false;
+    if (!memStoreHalf(0x20000002, 0xdef0))
+        return false;
+    if (!memLoad(0x20000000, word))
+        return false;
+    if (word != 0xdef05abc) {
+        log(LOG_ERROR, "ARMKinetisDebug: Halfword-wide AHB write seems broken! (Test word = %08x)", word);
+        return false;
+    }
+    if (!memLoadHalf(0x20000002, half))
+        return false;
+    if (half != 0xdef0) {
+        log(LOG_ERROR, "ARMKinetisDebug: Halfword-wide AHB read seems broken! (Test half = %04x)", half);
         return false;
     }