m68k: implement movep instruction

This patch implements movep instruction. It moves data between a data register
and alternate bytes within the address space starting at the location
specified and incrementing by two.

It was designed for the original 68000 and used in firmwares for
interfacing the 8-bit peripherals through the 16-bit data bus.
Without this patch opcode for this instruction is recognized as some bitop.

Signed-off-by: Pavel Dovgalyuk <[email protected]>
Signed-off-by: Mihail Abakumov <[email protected]>
Tested-by: Laurent Vivier <[email protected]>
Reviewed-by: Laurent Vivier <[email protected]>
Message-Id: <20180206124431.31433.91946.stgit@pasha-VirtualBox>
Signed-off-by: Laurent Vivier <[email protected]>

diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
index 6a80be009bfe6c1ab33d0780390011da7034b6ee..30267144714d9aef92e1de9e6bf08239f29dc1e6 100644 (file)
--- a/target/m68k/cpu.c
+++ b/target/m68k/cpu.c
@@ -113,6 +113,7 @@ static void m68000_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_M68000);
     m68k_set_feature(env, M68K_FEATURE_USP);
     m68k_set_feature(env, M68K_FEATURE_WORD_INDEX);
+    m68k_set_feature(env, M68K_FEATURE_MOVEP);
 }
 
 static void m68020_cpu_initfn(Object *obj)
@@ -135,6 +136,7 @@ static void m68020_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_BKPT);
     m68k_set_feature(env, M68K_FEATURE_RTD);
     m68k_set_feature(env, M68K_FEATURE_CHK2);
+    m68k_set_feature(env, M68K_FEATURE_MOVEP);
 }
 #define m68030_cpu_initfn m68020_cpu_initfn
 

diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
index 627fb787b6546128a7fa8ec50c290cd0f976ed68..1d79885222db89d679c0d0381e86354e4136d1b6 100644 (file)
--- a/target/m68k/cpu.h
+++ b/target/m68k/cpu.h
@@ -492,6 +492,7 @@ enum m68k_features {
     M68K_FEATURE_RTD,
     M68K_FEATURE_CHK2,
     M68K_FEATURE_M68040, /* instructions specific to MC68040 */
+    M68K_FEATURE_MOVEP,
 };
 
 static inline int m68k_feature(CPUM68KState *env, int feature)

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 34db97b8a04063da016988d036fadf9303addc99..70c7583621dd53c39d95c19198922e9a854ad1ff 100644 (file)
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -2078,6 +2078,51 @@ DISAS_INSN(movem)
     tcg_temp_free(addr);
 }
 
+DISAS_INSN(movep)
+{
+    uint8_t i;
+    int16_t displ;
+    TCGv reg;
+    TCGv addr;
+    TCGv abuf;
+    TCGv dbuf;
+
+    displ = read_im16(env, s);
+
+    addr = AREG(insn, 0);
+    reg = DREG(insn, 9);
+
+    abuf = tcg_temp_new();
+    tcg_gen_addi_i32(abuf, addr, displ);
+    dbuf = tcg_temp_new();
+
+    if (insn & 0x40) {
+        i = 4;
+    } else {
+        i = 2;
+    }
+
+    if (insn & 0x80) {
+        for ( ; i > 0 ; i--) {
+            tcg_gen_shri_i32(dbuf, reg, (i - 1) * 8);
+            tcg_gen_qemu_st8(dbuf, abuf, IS_USER(s));
+            if (i > 1) {
+                tcg_gen_addi_i32(abuf, abuf, 2);
+            }
+        }
+    } else {
+        for ( ; i > 0 ; i--) {
+            tcg_gen_qemu_ld8u(dbuf, abuf, IS_USER(s));
+            tcg_gen_deposit_i32(reg, reg, dbuf, (i - 1) * 8, 8);
+            if (i > 1) {
+                tcg_gen_addi_i32(abuf, abuf, 2);
+            }
+        }
+    }
+    tcg_temp_free(abuf);
+    tcg_temp_free(dbuf);
+}
+
 DISAS_INSN(bitop_im)
 {
     int opsize;
@@ -5678,6 +5723,7 @@ void register_m68k_insns (CPUM68KState *env)
     BASE(bitop_reg, 0140, f1c0);
     BASE(bitop_reg, 0180, f1c0);
     BASE(bitop_reg, 01c0, f1c0);
+    INSN(movep,     0108, f138, MOVEP);
     INSN(arith_im,  0280, fff8, CF_ISA_A);
     INSN(arith_im,  0200, ff00, M68000);
     INSN(undef,     02c0, ffc0, M68000);