cmdline support

Makefile

@@ -5,7 +5,7 @@ EMULATOR = ./amach
 ASFLAGS = -march=rv32imac -mabi=ilp32 -nostdlib -s -static -fno-pic -fno-pie -mno-relax
 LDFLAGS = -Wl,-Ttext=0x100b0 -Wl,--build-id=none
 
-all: rv32imac_tests.bin rv32imac_syscall_tests.bin rv32imac_tests.elf rv32imac_syscall_tests.elf
+all: rv32imac_tests.bin rv32imac_syscall_tests.bin rv32imac_args_tests.bin rv32imac_tests.elf rv32imac_syscall_tests.elf rv32imac_args_tests.elf
 
 rv32imac_tests.elf: rv32imac_tests.s
 	$(CC) $(ASFLAGS) $(LDFLAGS) rv32imac_tests.s -o rv32imac_tests.elf
@@ -19,7 +19,13 @@ rv32imac_syscall_tests.elf: rv32imac_syscall_tests.s
 rv32imac_syscall_tests.bin: rv32imac_syscall_tests.elf
 	$(OBJCOPY) -O binary rv32imac_syscall_tests.elf rv32imac_syscall_tests.bin
 
-run: rv32imac_tests.bin rv32imac_syscall_tests.bin rv32imac_tests.elf rv32imac_syscall_tests.elf
+rv32imac_args_tests.elf: rv32imac_args_tests.s
+	$(CC) $(ASFLAGS) $(LDFLAGS) rv32imac_args_tests.s -o rv32imac_args_tests.elf
+
+rv32imac_args_tests.bin: rv32imac_args_tests.elf
+	$(OBJCOPY) -O binary rv32imac_args_tests.elf rv32imac_args_tests.bin
+
+run: rv32imac_tests.bin rv32imac_syscall_tests.bin rv32imac_args_tests.bin rv32imac_tests.elf rv32imac_syscall_tests.elf rv32imac_args_tests.elf
 	@echo "Running CPU instruction tests (binary)..."
 	$(EMULATOR) rv32imac_tests.bin
 	@echo "Running CPU instruction tests (ELF)..."
@@ -32,6 +38,10 @@ run: rv32imac_tests.bin rv32imac_syscall_tests.bin rv32imac_tests.elf rv32imac_s
 	rm -rf test_dir test_link.txt test_output.txt test_output_new.txt
 	ln -sf test_output_new.txt test_link.txt
 	$(EMULATOR) rv32imac_syscall_tests.elf
+	@echo "Running command line arguments tests (binary)..."
+	$(EMULATOR) rv32imac_args_tests.bin arg1 arg2
+	@echo "Running command line arguments tests (ELF)..."
+	$(EMULATOR) rv32imac_args_tests.elf arg1 arg2
 	@echo "Testing standard ebreak..."
 	@echo "115 0 16 0" | awk -f amach.awk 2>&1 | grep -q "Fatal: EBREAK"
 	@echo "Testing compressed c.ebreak..."
@@ -39,6 +49,6 @@ run: rv32imac_tests.bin rv32imac_syscall_tests.bin rv32imac_tests.elf rv32imac_s
 	@echo "All tests PASSED!"
 
 clean:
-	rm -rf rv32imac_tests.elf rv32imac_tests.bin rv32imac_syscall_tests.elf rv32imac_syscall_tests.bin test_dir test_link.txt test_output.txt test_output_new.txt
+	rm -rf rv32imac_tests.elf rv32imac_tests.bin rv32imac_syscall_tests.elf rv32imac_syscall_tests.bin rv32imac_args_tests.elf rv32imac_args_tests.bin test_dir test_link.txt test_output.txt test_output_new.txt
 
 .PHONY: all run clean

README.md

@@ -19,17 +19,17 @@ First, decide where your program needs to be loaded in memory. The default LVA (
 
 Then, most probably, you'll want to use the provided wrapper:
 ```sh
-[LVA=...] ./amach path/to/program.bin
+[LVA=...] ./amach path/to/program.bin [...arguments]
 ```
 
 Or you can run the following:
 ```sh
-od -An -v -tu1 path/to/program.bin | POSIXLY_CORRECT=1 awk -f amach.awk [-v LVA=...]
+od -An -v -tu1 path/to/program.bin | POSIXLY_CORRECT=1 awk -f amach.awk [-v LVA=...] [-v CMD_OPTS=...]
 ```
 
 But in case you already have a program in the `.dec` format, you can pass it directly to AWK:
 ```sh
-POSIXLY_CORRECT=1 awk -f amach.awk [-v LVA=...] -- path/to/program.dec
+POSIXLY_CORRECT=1 awk -f amach.awk [-v LVA=...] [-v CMD_OPTS=...] -- path/to/program.dec
 ```
 
 ### ELF Executables
@@ -41,7 +41,7 @@ POSIXLY_CORRECT=1 awk -f amach.awk [-v LVA=...] -- path/to/program.dec
 
 You can launch ELF files directly using the wrapper or via the same pipe pipeline:
 ```sh
-./amach path/to/program.elf
+./amach path/to/program.elf [...arguments]
 ```
 
 ## Support

amach

@@ -1,4 +1,16 @@
 #!/bin/sh
-# A-Machine .bin launcher wrapper
+# A-Machine .bin/.elf launcher wrapper
 [ -z "$LVA" ] && LVA=65712 # 0x100b0
-od -An -v -tu1 "$1" | POSIXLY_CORRECT=1 awk -f amach.awk -v LVA="$LVA"
+SEP=$(printf '\001')
+CMD_OPTS=""
+first=1
+for arg in "$@"; do
+  if [ "$first" = 1 ]; then
+    CMD_OPTS="$arg"
+    first=0
+  else
+    CMD_OPTS="$CMD_OPTS$SEP$arg"
+  fi
+done
+[ -z "$AWK" ] && AWK=awk
+od -An -v -tu1 "$1" | POSIXLY_CORRECT=1 $AWK -f amach.awk -v LVA="$LVA" -v CMD_OPTS="$CMD_OPTS"

amach.awk

@@ -781,6 +781,35 @@ END {
     LVA = e_entry
   }
 
+  # Setup command-line arguments on the stack
+  n = 0
+  if(length(CMD_OPTS) > 0) n = split(CMD_OPTS, args, "\001")
+  else {
+    n = 1
+    args[1] = "amach"
+  }
+
+  sp = getreg(2)
+  for(i = n; i >= 1; i--) {
+    len = length(args[i])
+    sp = sp - (len + 1)
+    for(j = 1; j <= len; j++)
+      MEM[uint32(sp + j - 1)] = ord(substr(args[i], j, 1))
+    MEM[uint32(sp + len)] = 0
+    argv_ptr[i] = sp
+  }
+
+  sp = sp - (sp % 16)
+  sp = sp - 4 * (n + 3)
+  sp = sp - (sp % 16)
+
+  write_word(sp, n)
+  for(i = 1; i <= n; i++) write_word(sp + 4 * i, argv_ptr[i])
+  write_word(sp + 4 * (n + 1), 0)
+  write_word(sp + 4 * (n + 2), 0)
+
+  setreg(2, sp)
+
   memsize = pc - LVA
   pc = LVA
   while(pc > -1) {

rv32imac_args_tests.s

@@ -0,0 +1,91 @@
+.section .text
+.option norvc
+.global _start
+
+# Helper macro to exit with code if condition fails
+.macro ASSERT_EQ reg, val, error_code
+  li t4, \val
+  beq \reg, t4, .L_ok_\@
+  li a0, \error_code
+  li a7, 93
+  ecall
+.L_ok_\@:
+.endm
+
+# Compare string at register \str_reg with data label \label, exit with \error_code if not equal
+.macro ASSERT_STR_EQ str_reg, label, error_code
+  la t0, \label
+  mv t1, \str_reg
+.L_loop_\@:
+  lbu t2, 0(t0)
+  lbu t3, 0(t1)
+  bne t2, t3, .L_fail_\@
+  beqz t2, .L_ok_\@
+  addi t0, t0, 1
+  addi t1, t1, 1
+  j .L_loop_\@
+.L_fail_\@:
+  li a0, \error_code
+  li a7, 93
+  ecall
+.L_ok_\@:
+.endm
+
+_start:
+  # sp + 0: argc
+  # sp + 4: argv[0]
+  # sp + 8: argv[1]
+  # sp + 12: argv[2]
+
+  # 1. Print verification start message
+  li a7, 64       # sys_write
+  li a0, 1        # stdout
+  la a1, msg_start
+  li a2, 32       # message length
+  ecall
+
+  # 2. Check argc == 3
+  lw t0, 0(sp)
+  ASSERT_EQ t0, 3, 10
+
+  # 3. Check argv[0] is not null and not empty
+  lw t0, 4(sp)
+  beqz t0, .L_argv0_bad
+  lbu t1, 0(t0)
+  beqz t1, .L_argv0_bad
+  j .L_argv0_ok
+.L_argv0_bad:
+  li a0, 11
+  li a7, 93
+  ecall
+.L_argv0_ok:
+
+  # 4. Check argv[1] == "arg1"
+  lw t0, 8(sp)
+  ASSERT_STR_EQ t0, str_arg1, 12
+
+  # 5. Check argv[2] == "arg2"
+  lw t0, 12(sp)
+  ASSERT_STR_EQ t0, str_arg2, 13
+
+  # 6. Print success message
+  li a7, 64       # sys_write
+  li a0, 1        # stdout
+  la a1, msg_success
+  li a2, 32       # message length
+  ecall
+
+  # 7. Exit with code 0 on success
+  li a0, 0
+  li a7, 93
+  ecall
+
+.section .rodata
+msg_start:
+  .ascii "Running Command Line Args Tests\n"
+msg_success:
+  .ascii "Command Line Args Tests PASSED!\n"
+str_arg1:
+  .asciz "arg1"
+str_arg2:
+  .asciz "arg2"