IAR Thumb2 ASM: fixes

Don't assign constants to registers with IAR.
Don't assume register usage in AES_set_encrypt_key.

Author: SparkiDev

wolfcrypt/src/port/arm/thumb2-aes-asm.S

@@ -39,7 +39,7 @@
 #ifdef WOLFSSL_ARMASM_INLINE
 
 #ifdef WOLFSSL_ARMASM
-#if !defined(__aarch64__) && defined(__arm__)
+#if !defined(__aarch64__) && defined(__thumb__)
 
 #ifdef __IAR_SYSTEMS_ICC__
 #define __asm__        asm
@@ -84,8 +84,8 @@ void Transform_Sha256_Len(wc_Sha256* sha256, const byte* data, word32 len)
     register wc_Sha256* sha256 __asm__ ("r0") = (wc_Sha256*)sha256_p;
     register const byte* data __asm__ ("r1") = (const byte*)data_p;
     register word32 len __asm__ ("r2") = (word32)len_p;
-#endif /* !WOLFSSL_NO_VAR_ASSIGN_REG */
     register uint32_t* L_SHA256_transform_len_k_c __asm__ ("r3") = (uint32_t*)&L_SHA256_transform_len_k;
+#endif /* !WOLFSSL_NO_VAR_ASSIGN_REG */
 
     __asm__ __volatile__ (
         "SUB	sp, sp, #0xc0\n\t"
@@ -101,7 +101,7 @@ void Transform_Sha256_Len(wc_Sha256* sha256, const byte* data, word32 len)
         "STRD	r10, r11, [sp, #88]\n\t"
         /* Start of loop processing a block */
         "\n"
-    "L_SHA256_transform_len_begin_%=:\n\t"
+    "L_SHA256_transform_len_begin:\n\t"
         /* Load, Reverse and Store W - 64 bytes */
         "LDR	r4, [%[data]]\n\t"
         "LDR	r5, [%[data], #4]\n\t"
@@ -149,7 +149,7 @@ void Transform_Sha256_Len(wc_Sha256* sha256, const byte* data, word32 len)
         "MOV	r12, #0x3\n\t"
         /* Start of 16 rounds */
         "\n"
-    "L_SHA256_transform_len_start_%=:\n\t"
+    "L_SHA256_transform_len_start:\n\t"
         /* Round 0 */
         "LDR	r5, [%[sha256], #16]\n\t"
         "LDR	r6, [%[sha256], #20]\n\t"
@@ -905,9 +905,9 @@ void Transform_Sha256_Len(wc_Sha256* sha256, const byte* data, word32 len)
         "ADD	r3, r3, #0x40\n\t"
         "SUBS	r12, r12, #0x1\n\t"
 #if defined(__GNUC__) || defined(__ICCARM__) || defined(__IAR_SYSTEMS_ICC__)
-        "BNE	L_SHA256_transform_len_start_%=\n\t"
+        "BNE	L_SHA256_transform_len_start\n\t"
 #else
-        "BNE.N	L_SHA256_transform_len_start_%=\n\t"
+        "BNE.N	L_SHA256_transform_len_start\n\t"
 #endif
         /* Round 0 */
         "LDR	r5, [%[sha256], #16]\n\t"
@@ -1450,12 +1450,17 @@ void Transform_Sha256_Len(wc_Sha256* sha256, const byte* data, word32 len)
         "SUB	r3, r3, #0xc0\n\t"
         "ADD	%[data], %[data], #0x40\n\t"
 #if defined(__GNUC__) || defined(__ICCARM__) || defined(__IAR_SYSTEMS_ICC__)
-        "BNE	L_SHA256_transform_len_begin_%=\n\t"
+        "BNE	L_SHA256_transform_len_begin\n\t"
 #else
-        "BNE.N	L_SHA256_transform_len_begin_%=\n\t"
+        "BNE.N	L_SHA256_transform_len_begin\n\t"
 #endif
         "ADD	sp, sp, #0xc0\n\t"
-        : [sha256] "+r" (sha256), [data] "+r" (data), [len] "+r" (len), [L_SHA256_transform_len_k] "+r" (L_SHA256_transform_len_k_c)
+        : [sha256] "+r" (sha256), [data] "+r" (data), [len] "+r" (len),
+#ifndef WOLFSSL_NO_VAR_ASSIGN_REG
+         [L_SHA256_transform_len_k] "+r" (L_SHA256_transform_len_k_c)
+#else
+         [L_SHA256_transform_len_k] "r" (L_SHA256_transform_len_k)
+#endif /* WOLFSSL_NO_VAR_ASSIGN_REG */
         :
         : "memory", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12"
     );
@@ -1465,7 +1470,7 @@ void Transform_Sha256_Len(wc_Sha256* sha256, const byte* data, word32 len)
 #endif /* !NO_SHA256 */
 #endif /* !__aarch64__ && __thumb__ */
 #endif /* WOLFSSL_ARMASM */
-#endif /* !defined(__aarch64__) && defined(__arm__) */
+#endif /* !defined(__aarch64__) && defined(__thumb__) */
 #endif /* WOLFSSL_ARMASM */
 
 #endif /* WOLFSSL_ARMASM_INLINE */