usr: Add initial OSMX64 emulator sources

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

1 files changed, 127 insertions, 0 deletions

diff --git a/usr.bin/oemu/emu.c b/usr.bin/oemu/emu.c
new file mode 100644
index 0000000..1b4280b
--- /dev/null
+++ b/usr.bin/oemu/emu.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * 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 Hyra 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.
+ */
+
+#include <sys/errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <oemu/cpu.h>
+
+static struct oemu_cpu core_0;
+struct sysmem g_mem;
+
+static void
+help(void)
+{
+    printf(
+        "OSMORA OSMX64 Emulator\n"
+        "usage: oemu <binary file>\n"
+    );
+}
+
+/*
+ * Allocate and initialize platform
+ * memory.
+ */
+static int
+mem_init(void)
+{
+    printf("allocating 0x%x bytes of memory\n", MEMORY_SIZE);
+    g_mem.mem_size = MEMORY_SIZE;
+    g_mem.mem = malloc(MEMORY_SIZE);
+    if (g_mem.mem == NULL) {
+        printf("failed to allocate memory\n");
+        return -1;
+    }
+}
+
+/*
+ * Load a program specified by a path into
+ * memory for execution.
+ */
+static int
+program_load(const char *path, paddr_t loadoff)
+{
+    void *mem = g_mem.mem;
+    size_t size;
+    int fd;
+
+    fd = open(path, O_RDONLY);
+    if (fd < 0) {
+        printf("failed to open \"%s\"\n", path);
+        return -ENOENT;
+    }
+
+    /* Grab the size of the file */
+    size = lseek(fd, 0, SEEK_END);
+    lseek(fd, loadoff, SEEK_SET);
+    printf("loading size %d\n", size);
+
+    /* Is it too big? */
+    if (size >= g_mem.mem_size) {
+        printf("program too big !! (memsize=%x)\n", g_mem.mem_size);
+        close(fd);
+        return -1;
+    }
+
+    printf("read data into %p\n", mem);
+    printf("read %d bytes\n", read(fd, mem, size));
+    close(fd);
+    return 0;
+}
+
+int
+main(int argc, char **argv)
+{
+    if (argc < 2) {
+        help();
+        return -1;
+    }
+
+    /* Initialize memory */
+    if (mem_init() < 0) {
+        return -1;
+    }
+
+    /* Put the CPU in a known state */
+    cpu_reset(&core_0);
+
+    /*
+     * Load the program and send the little guy off
+     * to start nomming those 32-bit instructions
+     */
+    if (program_load(argv[1], 0x00000000) < 0) {
+        return -1;
+    }
+    cpu_kick(&core_0, &g_mem);
+    free(g_mem.mem);
+    return 0;
+}