README.md

@@ -1,12 +0,0 @@
-# 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

@@ -1,19 +0,0 @@
-# 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

@@ -0,0 +1,16 @@
+.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

@@ -1,17 +0,0 @@
-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

@@ -1,69 +1,12 @@
-# Define variables
+.section .text
-.data
+.globl _start
-.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
 
-# Main program entry point
+_start:
-.globl start
+    # Call the hello function
-.text
+    lui a0, %hi(_hello)    # Load upper immediate of _hello address
-start:
+    addi a0, a0, %lo(_hello)  # Add lower immediate of _hello address
-    call test_routine
+    jalr ra, a0, 0          # Jump and link to _hello, ra is return address
-    call hello_manual
-    # call hello # This doesn't work
-    call end
-    ebreak
 
-# Arbitrary test routine
+    # Exit the program
-test_routine:
+    li a7, 10               # syscall number for exit
-    la a0, num1    # Load the address of num1 into register a6
+    ecall                   # Make the system call to exit
-    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

@@ -10,10 +10,8 @@ SIZE = 		${CROSS}-size
 TARGET = bin.elf
 
 # QEMU command and flags
-# QEMU = qemu-riscv64-static
+QEMU = qemu-riscv64-static
-QEMU = qemu-system-riscv64
+QEMU_FLAGS =
-QEMU_FLAGS += --machine virt#	# Use the virt machine
-QEMU_FLAGS += --nographic#		# No graphical output
 
 # Flags for compiler and assembler
 CFLAGS += -static#				# Use static linking
@@ -25,13 +23,6 @@ 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
@@ -52,7 +43,7 @@ OBJS := $(AS_SRCS:.s=.o)
 
 # Default target
 all: $(OBJS)
-	@$(LD) $(LDFLAGS) -o $(TARGET) $(OBJS)
+	@$(CC) $(CFLAGS) -o $(TARGET) $(OBJS) 
 	@echo "LD $(OBJS)"
 
 # Compile assembly sources
@@ -61,9 +52,8 @@ all: $(OBJS)
 	@echo "CC $<"
 
 # Run the binary in QEMU
-run: all	
+run: all
-	@echo "To exit: Ctrl+A, X"
+	$(QEMU) $(QEMU_FLAGS) ./$(TARGET)
-	@$(QEMU) $(QEMU_FLAGS) -bios $(TARGET)
 
 # View the text section of the binary
 inspect: all