PoC msp430 register/flag support

lzss.h

@@ -0,0 +1,74 @@
+/* LZSS encoder-decoder (Haruhiko Okumura; public domain) */
+/* Modified by Clyne Sullivan to focus on streamed decompression. */
+
+#ifndef EOF
+#define EOF (-1)
+#endif
+
+#define EI 8  /* typically 10..13 */
+#define EJ  3  /* typically 4..5 */
+#define N (1 << EI)  /* buffer size */
+#define F ((1 << EJ) + 1)  /* lookahead buffer size */
+
+static unsigned char buffer[N * 2];
+static const unsigned char *inbuffer;
+static unsigned int insize, inidx;
+static int buf, mask;
+
+/* Prepares decode() to decompress the given data. */
+void lzssinit(const unsigned char *inb, unsigned int ins)
+{
+    inbuffer = inb;
+    insize = ins;
+    inidx = 0;
+    buf = 0;
+    mask = 0;
+}
+
+int getbit(int n) /* get n bits */
+{
+    int i, x;
+
+    x = 0;
+    for (i = 0; i < n; i++) {
+        if (mask == 0) {
+            if (inidx >= insize)
+                return EOF;
+            buf = inbuffer[inidx++];
+            mask = 128;
+        }
+        x <<= 1;
+        if (buf & mask) x++;
+        mask >>= 1;
+    }
+    return x;
+}
+
+/* handleoutput() receives each decompressed byte, return zero if want more. */
+int decode(int (*handleoutput)(int))
+{
+    int i, j, k, r, c, ret;
+
+    for (i = 0; i < N - F; i++) buffer[i] = ' ';
+    r = N - F;
+    while ((c = getbit(1)) != EOF) {
+        if (c) {
+            if ((c = getbit(8)) == EOF) break;
+            if ((ret = handleoutput(c)))
+                return ret;
+            buffer[r++] =(unsigned char) c;  r &= (N - 1);
+        } else {
+            if ((i = getbit(EI)) == EOF) break;
+            if ((j = getbit(EJ)) == EOF) break;
+            for (k = 0; k <= j + 1; k++) {
+                c = buffer[(i + k) & (N - 1)];
+                if ((ret = handleoutput(c)))
+                    return ret;
+                buffer[r++] = (unsigned char)c;  r &= (N - 1);
+            }
+        }
+    }
+
+    return EOF;
+}
+

msp430.cpp

@@ -16,6 +16,7 @@
 // 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
 
 #include <algorithm>
+#include <cctype>
 
 #include <msp430.h>
 
@@ -24,10 +25,22 @@
 #include "state.hpp"
 #include "types.hpp"
 
+#include "lzss.h"
+static const
+#include "msp430fr2476_all.h"
+
+#define MCLK_FREQ_MHZ (16)
+#define LZSS_MAGIC_SEPARATOR (0xFB)
+
 using DoubleCell = Cell;
 
 static char strbuf[80];
 
+static uint8_t lzword[32];
+static int lzwlen;
+static uint8_t lzbuf[32];
+static uint8_t *lzptr;
+
 static void serput(int c);
 static void serputs(const char *s);
 static void printint(DoubleCell n, int base);
@@ -37,7 +50,6 @@ static void initGPIO();
 static void initClock();
 static void initUART();
 static void Software_Trim();
-#define MCLK_FREQ_MHZ (16)
 
 static void doparse();
 
@@ -55,7 +67,7 @@ constexpr WordSet words (
     Word("@",         WordWrap<peek>),
     Word("c@",        WordWrap<peek, [] { *sp() &= 0xFF; }>),
     Word("!",         WordWrap<[] { auto a = (Cell *)pop(); *a = pop(); }>),
-    Word("c!",        WordWrap<[] { auto a = (char *)pop(); *a = pop(); }>),
+    Word("c!",        WordWrap<[] { auto a = (char *)pop(); *a = (char)pop(); }>),
     Word("_d",        WordWrap<[] { *sp() += (Cell)DICT.data(); }>),
     Word("_jmp",      WordWrap<[] { jump((FuncList)*++IP); }>),
     Word("_jmp0",     WordWrap<[] {
@@ -193,6 +205,45 @@ void printint(DoubleCell n, int base)
     serput(' ');
 }
 
+int findword(const char *word, int len)
+{
+    uint8_t *ptr = lzword;
+    for (int i = 0; i < len; ++i) {
+        if (islower(word[i]))
+            *ptr++ = word[i] - 32;
+        else
+            *ptr++ = word[i];
+    }
+    lzwlen = (int)(ptr - lzword);
+
+    lzptr = lzbuf;
+    lzssinit(msp430fr2476_all_lzss, msp430fr2476_all_lzss_len);
+
+    auto ret = decode([](int c) {
+        if (c != LZSS_MAGIC_SEPARATOR) {
+            *lzptr++ = (uint8_t)c;
+        } else {
+            if (lzwlen == lzptr - lzbuf - 2 && std::equal(lzbuf, lzptr - 2, lzword)) {
+                lzwlen = (*(lzptr - 2) << 8) | *(lzptr - 1);
+                return 1;
+            } else {
+                lzptr = lzbuf;
+            }
+        }
+        return 0;
+    });
+
+    if (ret == EOF) {
+        return -1;
+    } else {
+        push(lzwlen);
+        if (STATE)
+            compileliteral();
+
+        return 0;
+    }
+}
+
 void initMCU()
 {
     WDTCTL = WDTPW | WDTHOLD;

source/parse.cpp

@@ -22,6 +22,12 @@
 #include <cctype>
 #include <cstdlib>
 
+__attribute__((weak))
+int findword(const char *, int)
+{
+    return -1;
+}
+
 [[nodiscard]]
 static Error parseword(const char *start, const char *end)
 {
@@ -34,11 +40,13 @@ static Error parseword(const char *start, const char *end)
             } else {
                 result = execute1(word);
             }
-        } else if (isdigit(*start)) {
+        } else if (isdigit(*start) || (*start == '-' && isdigit(*(start + 1)))) {
             push(std::atoi(start));
 
             if (STATE)
                 compileliteral();
+        } else if (findword(start, end - start)) {
+            return Error::noword;
         }
     }
 

source/types.hpp

@@ -110,7 +110,8 @@ enum class Error : int {
     push,
     pop,
     rpush,
-    rpop
+    rpop,
+    noword
 };
 
 #endif // TYPES_HPP