target/avr: Add instruction translation - Register definitions

Start implementation of instructions by adding register definitions.

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-11-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

1 files changed, 142 insertions, 0 deletions

diff --git a/target/avr/translate.c b/target/avr/translate.c
new file mode 100644
index 0000000000..f802e6b29c
--- /dev/null
+++ b/target/avr/translate.c
@@ -0,0 +1,142 @@
+/*
+ * QEMU AVR CPU
+ *
+ * Copyright (c) 2019-2020 Michael Rolnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see
+ * <http://www.gnu.org/licenses/lgpl-2.1.html>
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/qemu-print.h"
+#include "tcg/tcg.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "tcg/tcg-op.h"
+#include "exec/cpu_ldst.h"
+#include "exec/helper-proto.h"
+#include "exec/helper-gen.h"
+#include "exec/log.h"
+#include "exec/translator.h"
+#include "exec/gen-icount.h"
+
+/*
+ *  Define if you want a BREAK instruction translated to a breakpoint
+ *  Active debugging connection is assumed
+ *  This is for
+ *  https://github.com/seharris/qemu-avr-tests/tree/master/instruction-tests
+ *  tests
+ */
+#undef BREAKPOINT_ON_BREAK
+
+static TCGv cpu_pc;
+
+static TCGv cpu_Cf;
+static TCGv cpu_Zf;
+static TCGv cpu_Nf;
+static TCGv cpu_Vf;
+static TCGv cpu_Sf;
+static TCGv cpu_Hf;
+static TCGv cpu_Tf;
+static TCGv cpu_If;
+
+static TCGv cpu_rampD;
+static TCGv cpu_rampX;
+static TCGv cpu_rampY;
+static TCGv cpu_rampZ;
+
+static TCGv cpu_r[NUMBER_OF_CPU_REGISTERS];
+static TCGv cpu_eind;
+static TCGv cpu_sp;
+
+static TCGv cpu_skip;
+
+static const char reg_names[NUMBER_OF_CPU_REGISTERS][8] = {
+    "r0",  "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
+    "r8",  "r9",  "r10", "r11", "r12", "r13", "r14", "r15",
+    "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
+    "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
+};
+#define REG(x) (cpu_r[x])
+
+enum {
+    DISAS_EXIT   = DISAS_TARGET_0,  /* We want return to the cpu main loop.  */
+    DISAS_LOOKUP = DISAS_TARGET_1,  /* We have a variable condition exit.  */
+    DISAS_CHAIN  = DISAS_TARGET_2,  /* We have a single condition exit.  */
+};
+
+typedef struct DisasContext DisasContext;
+
+/* This is the state at translation time. */
+struct DisasContext {
+    TranslationBlock *tb;
+
+    CPUAVRState *env;
+    CPUState *cs;
+
+    target_long npc;
+    uint32_t opcode;
+
+    /* Routine used to access memory */
+    int memidx;
+    int bstate;
+    int singlestep;
+
+    /*
+     * some AVR instructions can make the following instruction to be skipped
+     * Let's name those instructions
+     *     A   - instruction that can skip the next one
+     *     B   - instruction that can be skipped. this depends on execution of A
+     * there are two scenarios
+     * 1. A and B belong to the same translation block
+     * 2. A is the last instruction in the translation block and B is the last
+     *
+     * following variables are used to simplify the skipping logic, they are
+     * used in the following manner (sketch)
+     *
+     * TCGLabel *skip_label = NULL;
+     * if (ctx.skip_cond != TCG_COND_NEVER) {
+     *     skip_label = gen_new_label();
+     *     tcg_gen_brcond_tl(skip_cond, skip_var0, skip_var1, skip_label);
+     * }
+     *
+     * if (free_skip_var0) {
+     *     tcg_temp_free(skip_var0);
+     *     free_skip_var0 = false;
+     * }
+     *
+     * translate(&ctx);
+     *
+     * if (skip_label) {
+     *     gen_set_label(skip_label);
+     * }
+     */
+    TCGv skip_var0;
+    TCGv skip_var1;
+    TCGCond skip_cond;
+    bool free_skip_var0;
+};
+
+static bool avr_have_feature(DisasContext *ctx, int feature)
+{
+    if (!avr_feature(ctx->env, feature)) {
+        gen_helper_unsupported(cpu_env);
+        ctx->bstate = DISAS_NORETURN;
+        return false;
+    }
+    return true;
+}
+
+static bool decode_insn(DisasContext *ctx, uint16_t insn);
+#include "decode_insn.inc.c"