1 files changed, 113 insertions, 0 deletions
diff --git a/src/sys/arch/amd64/np/piir_conv.c b/src/sys/arch/amd64/np/piir_conv.c
new file mode 100644
index 0000000..bb94738
--- /dev/null
+++ b/src/sys/arch/amd64/np/piir_conv.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Description: Subsystem to convert PIIR to instruction bytes
+ * Author: Ian Marco Moffett
+ */
+
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/syslog.h>
+#include <machine/piir.h>
+#include <np/piir.h>
+#include <os/np.h>
+
+#define pr_trace(fmt, ...) printf("piir.conv: " fmt, ##__VA_ARGS__)
+#define pr_error(fmt, ...) printf("piir.conv: error: " fmt, ##__VA_ARGS__)
+
+typedef md_byte_t inst_t[8];
+
+/* Declare an instruction array */
+#define INST_DECL(...) ((inst_t)__VA_ARGS__)
+
+/* Near return [C2] */
+#define OP_NRET INST_DECL({0xC2})
+#define OP_NRET_LEN 1
+
+/* No-operation */
+#define OP_NOP INST_DECL({0x90})
+#define OP_NOP_LEN 1
+
+/* MOV R32, IMM32 (B8 + rd) */
+#define OP_LOAD32_R32(IMM32) INST_DECL({0xB8, (IMM32)})
+#define OP_LOAD32_R32_LEN 5
+
+/*
+ * Push an instruction byte into the virtual
+ * machine descriptor's code buffer
+ */
+static ssize_t
+vm_push(struct piir_vm *vm, inst_t inst, size_t len)
+{
+    for (int i = 0; i < len; ++i) {
+        if (vm->code_i >= sizeof(vm->code) - 1) {
+            return -1;
+        }
+
+        vm->code[vm->code_i++] = inst[i];
+    }
+    return len;
+}
+
+ssize_t
+md_piir_decode(struct np_work *work, struct piir_vm *vm, ir_byte_t input)
+{
+    struct piir_stack *stack;
+    ssize_t len;
+
+    if (vm == NULL) {
+        return -EINVAL;
+    }
+
+    vm->last_ir = input;
+    stack = work->piir_stack;
+
+    /*
+     * Convert the instruction from IR to machine
+     * code so that it actually may be executed
+     */
+    switch (input) {
+    case PIIR_RET_NUM:
+        if ((input = piir_pop(stack)) < 0) {
+            pr_error("bad input on PIIR_RET_NUM\n");
+            return input;
+        }
+
+        return vm_push(
+            vm, OP_LOAD32_R32(input),
+            OP_LOAD32_R32_LEN
+        );
+    case PIIR_NOP:
+        return vm_push(vm, OP_NOP, OP_NOP_LEN);
+    case PIIR_RET_NIL:
+        return vm_push(vm, OP_NRET, OP_NRET_LEN);
+    }
+    return 0;
+}