oasm: Parse and encode the "HLT" instruction

Signed-off-by: Ian Moffett <ian@osmora.org>

5 files changed, 32 insertions, 0 deletions

diff --git a/usr.bin/oasm/emit.c b/usr.bin/oasm/emit.c
index ee13582..cef90d7 100644
--- a/usr.bin/oasm/emit.c
+++ b/usr.bin/oasm/emit.c
@@ -220,6 +220,26 @@ emit_encode_add(struct emit_state *state, struct oasm_token *tok)
     return TAILQ_NEXT(tok, link);
 }
 
+/*
+ * Encode a HLT instruction
+ *
+ * 'hlt' - no operands
+ *
+ * Returns the next token on success,
+ * otherwise NULL.
+ */
+static struct oasm_token *
+emit_encode_hlt(struct emit_state *state, struct oasm_token *tok)
+{
+    inst_t curinst;
+
+    curinst.opcode = OSMX64_HLT;
+    curinst.rd = 0;
+    curinst.unused = 0;
+    emit_bytes(state, &curinst, sizeof(curinst));
+    return TAILQ_NEXT(tok, link);
+}
+
 int
 emit_osxm64(struct emit_state *state, struct oasm_token *tp)
 {
@@ -301,6 +321,9 @@ emit_process(struct oasm_state *oasm, struct emit_state *emit)
         case TT_ADD:
             curtok = emit_encode_add(emit, curtok);
             break;
+        case TT_HLT:
+            curtok = emit_encode_hlt(emit, curtok);
+            break;
         default:
             curtok = TAILQ_NEXT(curtok, link);
             break;
diff --git a/usr.bin/oasm/include/oasm/emit.h b/usr.bin/oasm/include/oasm/emit.h
index f4b4f77..b0a2fd1 100644
--- a/usr.bin/oasm/include/oasm/emit.h
+++ b/usr.bin/oasm/include/oasm/emit.h
@@ -60,6 +60,7 @@
 #define OSMX64_SLL      0x11    /* Shift left logical operation */
 #define OSMX64_SRL      0x12    /* Shift right logical operation */
 #define OSMX64_MOV_IMM  0x13    /* Data move operation from IMM */
+#define OSMX64_HLT      0x14    /* Halt the processor */
 
 /*
  * OSMX64 register definitions
diff --git a/usr.bin/oasm/include/oasm/lex.h b/usr.bin/oasm/include/oasm/lex.h
index 28ad52c..6ffaf79 100644
--- a/usr.bin/oasm/include/oasm/lex.h
+++ b/usr.bin/oasm/include/oasm/lex.h
@@ -95,6 +95,7 @@ typedef enum {
     TT_SUB,         /* 'sub' */
     TT_MUL,         /* 'mul' */
     TT_DIV,         /* 'div' */
+    TT_HLT,         /* 'hlt' */
 
     /* Register ops */
     TT_MOV,         /* 'mov' */
diff --git a/usr.bin/oasm/lex.c b/usr.bin/oasm/lex.c
index f8427e0..b3af2b1 100644
--- a/usr.bin/oasm/lex.c
+++ b/usr.bin/oasm/lex.c
@@ -45,6 +45,7 @@ static char putback = '\0';
 #define S_IMN_DIV  "div"
 #define S_IMN_INC  "inc"
 #define S_IMN_DEC  "dec"
+#define S_IMN_HLT  "hlt"
 
 /*
  * Returns 0 if a char is counted as a
@@ -179,6 +180,8 @@ token_arith(char *p)
         return TT_SUB;
     } else if (strcmp(p, S_IMN_DIV) == 0) {
         return TT_DIV;
+    } else if (strcmp(p, S_IMN_HLT) == 0) {
+        return TT_HLT;
     }
 
     return TT_UNKNOWN;
diff --git a/usr.bin/oasm/parse.c b/usr.bin/oasm/parse.c
index f87f903..6851935 100644
--- a/usr.bin/oasm/parse.c
+++ b/usr.bin/oasm/parse.c
@@ -42,6 +42,7 @@ static const char *tokstr[] = {
     [ TT_SUB ] = "sub",
     [ TT_MUL ] = "mul",
     [ TT_DIV ] = "div",
+    [ TT_HLT ] = "hlt",
     [ TT_COMMA ] = ",",
     [ TT_INC ] = "inc",
     [ TT_DEC ] = "dec",
@@ -140,6 +141,9 @@ parse_tok(struct oasm_state *state, struct oasm_token *tok)
     int error;
 
     switch (tok->type) {
+    case TT_HLT:
+        state->last = tok->type;
+        emit_osxm64(&emit_state, tok);
     case TT_MOV:
         state->last = tok->type;
         emit_osxm64(&emit_state, tok);