usr: Add initial OSMX64 emulator sources

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

6 files changed, 470 insertions, 0 deletions

diff --git a/usr.bin/oemu/Makefile b/usr.bin/oemu/Makefile
new file mode 100644
index 0000000..366208c
--- /dev/null
+++ b/usr.bin/oemu/Makefile
@@ -0,0 +1,7 @@
+include user.mk
+
+CFILES = $(shell find . -name "*.c")
+CFLAGS = -Iinclude/
+
+$(ROOT)/base/usr/bin/oemu:
+	gcc $(CFILES) -o $@ $(INTERNAL_CFLAGS) $(CFLAGS)
diff --git a/usr.bin/oemu/cpu.c b/usr.bin/oemu/cpu.c
new file mode 100644
index 0000000..61568f2
--- /dev/null
+++ b/usr.bin/oemu/cpu.c
@@ -0,0 +1,146 @@
+/*
+ * 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/param.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <oemu/cpu.h>
+#include <oemu/types.h>
+#include <oemu/osmx64.h>
+
+/*
+ * Decode the INST_MOV_IMM instruction
+ *
+ * @cpu: CPU that is executing
+ * @inst: Instruction dword
+ */
+static void
+cpu_mov_imm(struct oemu_cpu *cpu, inst_t *inst)
+{
+    struct cpu_regs *regs = &cpu->regs;
+
+    if (inst->rd > NELEM(regs->xreg)) {
+        printf("bad register operand for 'mov'\n");
+        return;
+    }
+
+    regs->xreg[inst->rd] = inst->imm;
+    printf("#%d -> x%d\n", inst->imm, inst->rd);
+}
+
+/*
+ * Decode the INST_INC instruction
+ *
+ * @cpu: CPU that is executing
+ * @inst: Instruction dword
+ */
+static void
+cpu_inc(struct oemu_cpu *cpu, inst_t *inst)
+{
+    struct cpu_regs *regs = &cpu->regs;
+    imm_t imm;
+
+    if (inst->rd > NELEM(regs->xreg)) {
+        printf("bad register operand for 'mov'\n");
+        return;
+    }
+
+    imm = regs->xreg[inst->rd]++;
+    printf("INC X%d [%x], new=%x\n", inst->rd,
+        imm, regs->xreg[inst->rd]);
+}
+
+/*
+ * Decode the INST_DEC instruction
+ *
+ * @cpu: CPU that is executing
+ * @inst: Instruction dword
+ */
+static void
+cpu_dec(struct oemu_cpu *cpu, inst_t *inst)
+{
+    struct cpu_regs *regs = &cpu->regs;
+    imm_t imm;
+
+    if (inst->rd > NELEM(regs->xreg)) {
+        printf("bad register operand for 'mov'\n");
+        return;
+    }
+
+    imm = regs->xreg[inst->rd]--;
+    printf("DEC X%d [%x], new=%x\n", inst->rd,
+        imm, regs->xreg[inst->rd]);
+}
+
+/*
+ * Reset a CPU to a default state
+ */
+void
+cpu_reset(struct oemu_cpu *cpu)
+{
+    struct cpu_regs *regs;
+
+    regs = &cpu->regs;
+    regs->ip = 0;
+    memset(regs->xreg, 0x0, sizeof(regs->xreg));
+}
+
+/*
+ * Main instruction execution loop.
+ */
+void
+cpu_kick(struct oemu_cpu *cpu, struct sysmem *mem)
+{
+    struct cpu_regs *regs = &cpu->regs;
+    inst_t *inst;
+    uint8_t *memp = mem->mem;
+
+    for (;;) {
+        inst = (inst_t *)&memp[regs->ip];
+
+        switch (inst->opcode) {
+        case INST_MOV_IMM:
+            cpu_mov_imm(cpu, inst);
+            break;
+        case INST_INC:
+            cpu_inc(cpu, inst);
+            break;
+        case INST_DEC:
+            cpu_dec(cpu, inst);
+            break;
+        }
+
+        if (regs->ip >= MEMORY_SIZE) {
+            break;
+        }
+
+        regs->ip += sizeof(*inst);
+    }
+}
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;
+}
diff --git a/usr.bin/oemu/include/oemu/cpu.h b/usr.bin/oemu/include/oemu/cpu.h
new file mode 100644
index 0000000..df4cc80
--- /dev/null
+++ b/usr.bin/oemu/include/oemu/cpu.h
@@ -0,0 +1,69 @@
+/*
+ * 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.
+ */
+
+#ifndef _OEMU_CPU_H_
+#define _OEMU_CPU_H_
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <oemu/types.h>
+
+#define MEMORY_SIZE 512
+
+/*
+ * System memory
+ *
+ * @mem: Data
+ * @mem_size: Memory size max
+ */
+struct sysmem {
+    void *mem;
+    size_t mem_size;
+};
+
+/*
+ * CPU register state
+ *
+ * @xreg: X<n>
+ * @ip: Instruction pointer
+ */
+struct cpu_regs {
+    reg_t xreg[16];
+    reg_t ip;
+};
+
+struct oemu_cpu {
+    struct cpu_regs regs;
+};
+
+void cpu_reset(struct oemu_cpu *cpu);
+void cpu_kick(struct oemu_cpu *cpu, struct sysmem *mem);
+
+#endif  /* !_OEMU_CPU_H_ */
diff --git a/usr.bin/oemu/include/oemu/osmx64.h b/usr.bin/oemu/include/oemu/osmx64.h
new file mode 100644
index 0000000..d7ea8b1
--- /dev/null
+++ b/usr.bin/oemu/include/oemu/osmx64.h
@@ -0,0 +1,82 @@
+/*
+ * 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.
+ */
+
+#ifndef _OEMU_OSMX64_H_
+#define _OEMU_OSMX64_H_
+
+#include <stdint.h>
+
+/* Opcodes */
+#define INST_NOP      0x00    /* No-operation */
+#define INST_ADD      0x01    /* Add operation */
+#define INST_SUB      0x02    /* Sub operation */
+#define INST_MUL      0x03    /* Multiply operation */
+#define INST_DIV      0x04    /* Divide operation */
+#define INST_INC      0x05    /* Increment operation */
+#define INST_DEC      0x06    /* Decrement operation */
+#define INST_OR       0x07    /* Bitwise OR operation */
+#define INST_XOR      0x08    /* Bitwise XOR operation */
+#define INST_AND      0x09    /* Bitwise AND operation */
+#define INST_NOT      0x10    /* Bitwise NOT operation */
+#define INST_SLL      0x11    /* Shift left logical operation */
+#define INST_SRL      0x12    /* Shift right logical operation */
+#define INST_MOV_IMM  0x13    /* Data move operation from IMM */
+
+/* Registers */
+#define REG_X0   0x00
+#define REG_X1   0x01
+#define REG_X2   0x02
+#define REG_X3   0x03
+#define REG_X4   0x04
+#define REG_X5   0x05
+#define REG_X6   0x06
+#define REG_X7   0x07
+#define REG_X8   0x08
+#define REG_X9   0x09
+#define REG_X10  0x0A
+#define REG_X11  0x0B
+#define REG_X12  0x0C
+#define REG_X13  0x0D
+#define REG_X14  0x0E
+#define REG_X15  0x0F
+#define REG_BAD  0xFF
+
+/*
+ * OSMX64 instruction format
+ */
+typedef struct {
+    uint8_t opcode;
+    uint8_t rd;
+    union {
+        uint16_t imm;
+        uint16_t unused;
+    };
+} inst_t;
+
+#endif  /* !_OEMU_OSMX64_H_ */
diff --git a/usr.bin/oemu/include/oemu/types.h b/usr.bin/oemu/include/oemu/types.h
new file mode 100644
index 0000000..0769c84
--- /dev/null
+++ b/usr.bin/oemu/include/oemu/types.h
@@ -0,0 +1,39 @@
+/*
+ * 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.
+ */
+
+#ifndef _OEMU_TYPES_H_
+#define _OEMU_TYPES_H_
+
+#include <sys/types.h>
+
+typedef uint64_t reg_t;
+typedef uintptr_t paddr_t;
+typedef uint16_t imm_t;
+
+#endif  /* !_OEMU_TYPES_H_ */