Semi-working output, still no exall

README.md

@@ -0,0 +1,12 @@
+# Risc-V Assembly Language Programming
+
+## Resources
+
+- [RISC-V Guru](https://risc-v.guru/) and [direct link to the instruction set](https://risc-v.guru/instructions/)
+- [RISC-V Greehsheet](https://raw.githubusercontent.com/rswinkle/riscv_book/master/references/riscv_greensheet.pdf) and its [large version](https://raw.githubusercontent.com/rswinkle/riscv_book/master/references/riscv_greensheet_large.pdf)
+- [RISC-V ISA Manual](https://riscv.org/wp-content/uploads/2017/05/riscv-spec-v2.2.pdf)
+- [RISC-V Specifications](https://riscv.org/technical/specifications/)
+
+### Misc
+
+- [RISC-V Assembly Language Programming](https://github.com/rswinkle/riscv_book/)

end.s

@@ -0,0 +1,19 @@
+# Just print the word 'exit' to the address 0x10000000
+.globl end
+end:
+    addi a0, x0, 0x65 # 'e'
+    li a1, 0x10000000
+    sb a0, (a1)
+
+    addi a0, x0, 0x78 # 'x'
+    sb a0, (a1)
+
+    addi a0, x0, 0x69 # 'i'
+    sb a0, (a1)
+
+    addi a0, x0, 0x74 # 't'
+    sb a0, (a1)
+
+    addi a0, x0, 0x0A
+    sb a0, (a1) # '\n'
+    ret

hello.s

@@ -1,16 +0,0 @@
-.section .text
-.globl _hello
-
-_hello:
-    # Write the string "Hello, World!\n" to stdout
-    la a0, msg              # Load the address of the string into a0
-    li a7, 4                # syscall number for write
-    li a1, 13               # Length of the string
-    li a2, 1                # File descriptor: stdout
-    ecall                   # Make the system call to write
-
-    ret                     # Return from the function
-
-.section .data
-msg:
-    .ascii "Hello, World!\n"

link.ld

@@ -0,0 +1,17 @@
+MEMORY {
+    SRAM (rwx) : ORIGIN = 0x20000000, LENGTH = 1024
+    DRAM (rwx) : ORIGIN = 0x80000000, LENGTH = 1024
+}
+
+SECTIONS {
+    .text : {
+        main.o(.text.*)
+        *(.text)
+    } > DRAM
+    .data : {
+        *(.data)
+    } > DRAM AT > SRAM
+    .bss : {
+        *(.bss)
+    } > DRAM
+}

main.s

@@ -1,12 +1,69 @@
-.section .text
+# Define variables
-.globl _start
+.data
+.align 4
+    num1: .word 5     # First number
+    num2: .word 7     # Second number
+    result: .word 0   # Variable to store the result
+    msg: .ascii "Hello, World!\n"
+    array: .space 100 # 100 bytes of space
 
-_start:
+# Main program entry point
-    # Call the hello function
+.globl start
-    lui a0, %hi(_hello)    # Load upper immediate of _hello address
+.text
-    addi a0, a0, %lo(_hello)  # Add lower immediate of _hello address
+start:
-    jalr ra, a0, 0          # Jump and link to _hello, ra is return address
+    call test_routine
+    call hello_manual
+    # call hello # This doesn't work
+    call end
+    ebreak
 
-    # Exit the program
+# Arbitrary test routine
-    li a7, 10               # syscall number for exit
+test_routine:
-    ecall                   # Make the system call to exit
+    la a0, num1    # Load the address of num1 into register a6
+    li a1, 10      # Load the value 10 into register a5
+    xori a2, a1, 0x1  # Calculate the value of a2
+    sw a1, 0(a0)    # Store the value in memory
+    ret
+
+# Prints "hello" manually
+hello_manual:	
+    addi a0, x0, 0x68
+	li a1, 0x10000000
+	sb a0, (a1) # 'h'
+
+	addi a0, x0, 0x65
+	sb a0, (a1) # 'e'
+
+	addi a0, x0, 0x6C
+	sb a0, (a1) # 'l'
+
+	addi a0, x0, 0x6C
+	sb a0, (a1) # 'l'
+
+	addi a0, x0, 0x6F
+	sb a0, (a1) # 'o'
+
+    addi a0, x0, 0x0A
+    sb a0, (a1) # '\n'
+    ret
+
+# Is supposed to print "Hello, World!\n" to stdout via ecall, but doesn't work
+hello:
+    # Write the string "Hello, World!\n" to stdout
+    la a0, msg              # Load the address of the string into a0
+    li a7, 4                # syscall number for write
+    li a1, 13               # Length of the string
+    li a2, 1                # File descriptor: stdout
+    ecall                   # Make the system call to write
+    ret                     # Return from the function
+
+# Another routine, presumably written for the rars emulator?
+hello2:
+    li a0, 0x1
+    la a1, msg
+    li a2, 13
+    li a7, 64
+    ecall
+
+# To avoid the program from exiting
+loop: j loop

makefile

@@ -10,8 +10,10 @@ SIZE = 		${CROSS}-size
 TARGET = bin.elf
 
 # QEMU command and flags
-QEMU = qemu-riscv64-static
+# QEMU = qemu-riscv64-static
-QEMU_FLAGS =
+QEMU = qemu-system-riscv64
+QEMU_FLAGS += --machine virt#	# Use the virt machine
+QEMU_FLAGS += --nographic#		# No graphical output
 
 # Flags for compiler and assembler
 CFLAGS += -static#				# Use static linking
@@ -23,6 +25,13 @@ CFLAGS += -march=rv64i			# Use RV64I ISA, i.e., integer only
 CFLAGS += -mabi=lp64			# Use LP64 ABI, i.e., 64-bit longs and pointers, 32-bit ints
 CFLAGS += -Os#					# Optimize for size
 
+LDFLAGS += -T link.ld			# Use the linker script
+LDFLAGS += --no-dynamic-linker
+LDFLAGS += -m elf64lriscv
+LDFLAGS += -static
+LDFLAGS += -nostdlib
+LDFLAGS += -s
+
 # Use GC=0 to disable garbage collection
 ifneq ($(GC), 0)
 	CFLAGS += -ffreestanding
@@ -43,7 +52,7 @@ OBJS := $(AS_SRCS:.s=.o)
 
 # Default target
 all: $(OBJS)
-	@$(CC) $(CFLAGS) -o $(TARGET) $(OBJS) 
+	@$(LD) $(LDFLAGS) -o $(TARGET) $(OBJS)
 	@echo "LD $(OBJS)"
 
 # Compile assembly sources
@@ -52,8 +61,9 @@ all: $(OBJS)
 	@echo "CC $<"
 
 # Run the binary in QEMU
-run: all
+run: all	
-	$(QEMU) $(QEMU_FLAGS) ./$(TARGET)
+	@echo "To exit: Ctrl+A, X"
+	@$(QEMU) $(QEMU_FLAGS) -bios $(TARGET)
 
 # View the text section of the binary
 inspect: all