diff options
Diffstat (limited to 'boot/asm-boot.s')
| -rw-r--r-- | boot/asm-boot.s | 894 |
1 files changed, 0 insertions, 894 deletions
diff --git a/boot/asm-boot.s b/boot/asm-boot.s deleted file mode 100644 index fca0d3f..0000000 --- a/boot/asm-boot.s +++ /dev/null @@ -1,894 +0,0 @@ -# s1 - Contains the current position in the source text. - -.global _start # Program entry point. - -.section .rodata - -.equ SOURCE_BUFFER_SIZE, 2048 - -asm_begin: .ascii ".text\n.global _start\n_start:\naddi sp, sp, -64\nsw ra, 60(sp)\nsw s0, 56(sp)\naddi s0, sp, 64\n" -.equ ASM_BEGIN_SIZE, . - asm_begin -asm_end: .ascii "addi a0, zero, 0\naddi a7, zero, 93\necall\nlw ra, 60(sp)\nlw s0, 56(sp)\naddi sp, sp, 64\nret\n" -.equ ASM_END_SIZE, . - asm_end -asm_program: .ascii ".bss\n" -.equ ASM_PROGRAM_SIZE, . - asm_program -asm_type: .ascii ".type " -.equ ASM_TYPE_SIZE, . - asm_type -asm_object: .ascii ", @object\n" -.equ ASM_OBJECT_SIZE, . - asm_object -asm_size: .ascii ".size " -.equ ASM_SIZE_SIZE, . - asm_size -asm_zero: .ascii ".zero " -.equ ASM_ZERO_SIZE, . - asm_zero -asm_global: .ascii ".global " -.equ ASM_GLOBAL_SIZE, . - asm_global - -token_begin: .string "begin" -token_end: .string "end" -token_import: .string "import" -token_open_paren: .string "(" -token_close_paren: .string ")" -token_open_square: .string "[" -token_assign: .string ":=" -token_var: .string "var" -token_comma: .string "," - -space: .ascii " " -comma: .ascii "," -new_line: .ascii "\n" -colon: .ascii ":" -digit_zero: .ascii "0" - -instruction_la: .ascii "la" -instruction_call: .ascii "call" -instruction_addi: .ascii "addi" -instruction_li: .ascii "li" -instruction_sw: .ascii "sw" -instruction_lw: .ascii "lw" - -register_a0: .ascii "a0" -register_sp: .ascii "sp" -register_a: .ascii "a" - -.section .bss -.global source_code -.type source_code, @object -.size source_code, SOURCE_BUFFER_SIZE -source_code: .zero SOURCE_BUFFER_SIZE - -.section .text - -.type _skip_spaces, @function -_skip_spaces: -.Lspace_loop_do: - lbu t0, (s1) # t0 = Current character. - - li t1, ' ' - beq t0, t1, .Lspace_loop_repeat - li t1, '\t' - beq t0, t1, .Lspace_loop_repeat - li t1, '\n' - beq t0, t1, .Lspace_loop_repeat - li t1, '\r' - beq t0, t1, .Lspace_loop_repeat - - j .Lspace_loop_end -.Lspace_loop_repeat: - addi s1, s1, 1 - j .Lspace_loop_do - -.Lspace_loop_end: - ret - -# Compares two string, which of one has a length, the other one is null-terminated. -# -# a0 - The address of the token string. -# a1 - The length of the string in a0. -# a2 - The address of the null-terminated string. -# -# If the strings match sets a0 to 0, otherwise sets it to 1. -.type _token_compare, @function -_token_compare: - addi t0, a0, 0 - addi t1, a1, 0 - addi t2, a2, 0 - -.Ltoken_compare_loop: - lbu t3, (t2) - - # Will only be 0 if the current character in the null terminated string is \0 and the remaining length of the - # another string is 0. - or t4, t3, t1 - beqz t4, .Ltoken_compare_equal - - beqz t1, .Ltoken_compare_not_equal - beqz t3, .Ltoken_compare_not_equal - - lbu t4, (t0) - bne t3, t4, .Ltoken_compare_not_equal - - addi t0, t0, 1 - addi t1, t1, -1 - addi t2, t2, 1 - j .Ltoken_compare_loop - -.Ltoken_compare_not_equal: - li a0, 1 - j .Ltoken_compare_end - -.Ltoken_compare_equal: - li a0, 0 - -.Ltoken_compare_end: - ret - -# Reads a token and returns its length in a0. -# _read_token doesn't change s1, it finds the length of the token s1 is pointing to. -.type _read_token, @function -_read_token: - # Prologue. - addi sp, sp, -16 - sw ra, 12(sp) - sw s0, 8(sp) - addi s0, sp, 16 - - lbu t0, (s1) # t0 = Current character. - sw zero, 4(sp) - - li t1, '.' - beq t0, t1, .Ltoken_character_single - - li t1, ',' - beq t0, t1, .Ltoken_character_single - - li t1, ':' - beq t0, t1, .Ltoken_character_colon - - li t1, ';' - beq t0, t1, .Ltoken_character_single - - li t1, '(' - beq t0, t1, .Ltoken_character_single - - li t1, ')' - beq t0, t1, .Ltoken_character_single - - li t1, '[' - beq t0, t1, .Ltoken_character_single - - li t1, ']' - beq t0, t1, .Ltoken_character_single - -.Ltoken_character_loop_do: # Expect an identifier or a number. - lw t6, 4(sp) - add t1, s1, t6 - lbu a0, (t1) # a0 = Current character. - - call is_alnum - - beqz a0, .Ltoken_character_end - lw t6, 4(sp) - addi t6, t6, 1 - sw t6, 4(sp) - j .Ltoken_character_loop_do - -.Ltoken_character_single: - lw t6, 4(sp) - addi t6, t6, 1 - sw t6, 4(sp) - j .Ltoken_character_end - -.Ltoken_character_colon: - lbu t0, 1(s1) # t0 = The character after the colon. - lw t6, 4(sp) - addi t6, t6, 1 - sw t6, 4(sp) - - li t1, '=' - beq t0, t1, .Ltoken_character_single - j .Ltoken_character_end - -.Ltoken_character_end: - lw a0, 4(sp) - - # Epilogue. - lw ra, 12(sp) - lw s0, 8(sp) - addi sp, sp, 16 - ret - -# Generate entry point symbol. -.type _compile_begin, @function -_compile_begin: - # Prologue. - addi sp, sp, -8 - sw ra, 4(sp) - sw s0, 0(sp) - addi s0, sp, 8 - - # Write initial assembler. - la a0, asm_begin - addi a1, zero, ASM_BEGIN_SIZE - call write_out - - addi s1, s1, 5 - - # Epilogue. - lw ra, 4(sp) - lw s0, 0(sp) - addi sp, sp, 8 - ret - -# Generate program termination code. -.type _compile_end, @function -_compile_end: - # Prologue. - addi sp, sp, -8 - sw ra, 4(sp) - sw s0, 0(sp) - addi s0, sp, 8 - - # Write closing assembler. - la a0, asm_end - addi a1, zero, ASM_END_SIZE - call write_out - - addi s1, s1, 3 - - # Epilogue. - lw ra, 4(sp) - lw s0, 0(sp) - addi sp, sp, 8 - ret - -# Ignores the import. -.type _compile_import, @function -_compile_import: - # Prologue. - addi sp, sp, -8 - sw ra, 4(sp) - sw s0, 0(sp) - addi s0, sp, 8 - - addi s1, s1, 6 - call _skip_spaces - call _read_token - add s1, s1, a0 # Skip the imported module name. - - # Epilogue. - lw ra, 4(sp) - lw s0, 0(sp) - addi sp, sp, 8 - ret - -# Compiles a procedure call. Expects s1 to point to the first argument. -# a0 - Pointer to the procedure name. -# a1 - Length of the procedure name. -# -# Returns the procedure result in a0. -.type _compile_call, @function -_compile_call: - # Prologue. - addi sp, sp, -32 - sw ra, 28(sp) - sw s0, 24(sp) - addi s0, sp, 32 - - sw a0, 20(sp) - sw a1, 16(sp) - sw zero, 12(sp) # Argument count for a procedure call. - -.Lcompile_call_paren: - call _skip_spaces - call _read_token - addi a1, a0, 0 - addi a0, s1, 0 - la a2, token_close_paren - call _token_compare - beqz a0, .Lcompile_call_complete - -.Lcompile_call_argument: - call _build_expression - - la a0, instruction_sw - li a1, 2 - call write_out - - la a0, space - li a1, 1 - call write_out - - la a0, register_a0 - li a1, 2 - call write_out - - la a0, comma - li a1, 1 - call write_out - - lw t0, 12(sp) # Argument count for a procedure call. - - # Only 8 arguments are supported with a0-a7. - # Save all arguments on the stack so they aren't overriden afterwards. - # The offset on the stack always has two digits in this case. - li t1, -4 - mul t1, t0, t1 - addi t1, t1, 52 - li t2, 10 - div t3, t1, t2 - rem t4, t1, t2 - addi t3, t3, '0' - addi t4, t4, '0' - - sw t3, 8(sp) - sw t4, 4(sp) - - addi a0, sp, 8 - li a1, 1 - call write_out - - addi a0, sp, 4 - li a1, 1 - call write_out - - la a0, token_open_paren - li a1, 1 - call write_out - - la a0, register_sp - li a1, 2 - call write_out - - la a0, token_close_paren - li a1, 1 - call write_out - - la a0, new_line - li a1, 1 - call write_out - - call _skip_spaces - call _read_token - addi a1, a0, 0 - addi a0, s1, 0 - la a2, token_comma - call _token_compare - - bnez a0, .Lcompile_call_paren - - lw t0, 12(sp) # Argument count for a procedure call. - addi t0, t0, 1 - sw t0, 12(sp) - - addi s1, s1, 1 # Skip the comma between the arguments. - j .Lcompile_call_argument - -.Lcompile_call_complete: - sw zero, 12(sp) - -.Lcompile_call_restore: - # Just go through all a0-a7 registers and read them from stack. - # If this stack value contains garbage, the procedure just shouldn't use it. - lw t0, 12(sp) - li t1, 7 - bgt t0, t1, .Lcompile_call_perform - - la a0, instruction_lw - li a1, 2 - call write_out - - la a0, space - li a1, 1 - call write_out - - la a0, register_a - li a1, 1 - call write_out - - lw t0, 12(sp) - addi t0, t0, '0' - sw t0, 8(sp) - - addi a0, sp, 8 - li a1, 1 - call write_out - - la a0, comma - li a1, 1 - call write_out - - lw t0, 12(sp) # Argument count for a procedure call. - - li t1, -4 - mul t1, t0, t1 - addi t1, t1, 52 - li t2, 10 - div t3, t1, t2 - rem t4, t1, t2 - addi t3, t3, '0' - addi t4, t4, '0' - - sw t3, 8(sp) - sw t4, 4(sp) - - addi a0, sp, 8 - li a1, 1 - call write_out - - addi a0, sp, 4 - li a1, 1 - call write_out - - la a0, token_open_paren - li a1, 1 - call write_out - - la a0, register_sp - li a1, 2 - call write_out - - la a0, token_close_paren - li a1, 1 - call write_out - - la a0, new_line - li a1, 1 - call write_out - - lw t0, 12(sp) # Increment. - addi t0, t0, 1 - sw t0, 12(sp) - - j .Lcompile_call_restore - -.Lcompile_call_perform: - la a0, instruction_call - li a1, 4 - call write_out - - la a0, space - li a1, 1 - call write_out - - lw a0, 20(sp) - lw a1, 16(sp) - call write_out - - la a0, new_line - li a1, 1 - call write_out - - call _skip_spaces - addi s1, s1, 1 # Skip the close paren. - - # Epilogue. - lw ra, 28(sp) - lw s0, 24(sp) - addi sp, sp, 32 - ret - -.type _compile, @function -compile: - # Prologue. - addi sp, sp, -16 - sw ra, 12(sp) - sw s0, 8(sp) - addi s0, sp, 16 - - # Write .bss section header for global variables. - la a0, asm_program - addi a1, zero, ASM_PROGRAM_SIZE - call write_out - - call _skip_spaces - addi s1, s1, 7 # Skip "program" keyword. - -.Lcharacter_loop_do: - call _skip_spaces - - lbu t0, (s1) # t0 = Current character. - beqz t0, .Lcharacter_loop_end - - call _read_token - sw a0, 4(sp) # Save the token length on the stack. - beqz a0, .Lcharacter_loop_end # No token read, there is unrecognized input. - - lw a0, 4(sp) - call _handle_token - - j .Lcharacter_loop_do -.Lcharacter_loop_end: - - # Epilogue. - lw ra, 12(sp) - lw s0, 8(sp) - addi sp, sp, 16 - ret - -# Evalutes an expression and saves the result in a0. -.type _build_expression, @function -_build_expression: - # Prologue. - addi sp, sp, -16 - sw ra, 12(sp) - sw s0, 8(sp) - addi s0, sp, 16 - - call _skip_spaces - call _read_token - sw s1, 4(sp) - sw a0, 0(sp) - - # Integer literal. - addi a0, s1, 0 - lb a0, (a0) - call is_digit - bnez a0, .Lbuild_expression_number_literal - - # Named identifier. - la a0, instruction_la - li a1, 2 - call write_out - - la a0, space - li a1, 1 - call write_out - - la a0, register_a0 - li a1, 2 - call write_out - - la a0, comma - li a1, 1 - call write_out - - lw a0, 4(sp) - lw a1, 0(sp) - call write_out - - la a0, new_line - li a1, 1 - call write_out - - j .Lbuild_expression_end - -.Lbuild_expression_number_literal: - la a0, instruction_li - li a1, 2 - call write_out - - la a0, space - li a1, 1 - call write_out - - la a0, register_a0 - li a1, 2 - call write_out - - la a0, comma - li a1, 1 - call write_out - - lw a0, 4(sp) - lw a1, 0(sp) - call write_out - - la a0, new_line - li a1, 1 - call write_out - - j .Lbuild_expression_end - -.Lbuild_expression_end: - lw a0, 0(sp) - add s1, s1, a0 - - # Epilogue. - lw ra, 12(sp) - lw s0, 8(sp) - addi sp, sp, 16 - ret - -# Compiles a statement beginning with an identifier. -.type _compile_identifier, @function -_compile_identifier: - # Prologue. - addi sp, sp, -32 - sw ra, 28(sp) - sw s0, 24(sp) - addi s0, sp, 32 - - # Save the pointer to the identifier and its length on the stack. - sw a0, 20(sp) - sw a1, 16(sp) - - add s1, s1, a1 - call _skip_spaces - call _read_token - - # Save the pointer and the length of the token following the identifier. - sw s1, 12(sp) - sw a0, 8(sp) - - add s1, s1, a0 # Skip that token. - call _skip_spaces - - lw a0, 12(sp) - lw a1, 8(sp) - la a2, token_assign - call _token_compare - beqz a0, .Lcompile_identifier_assign - - lw a0, 12(sp) - lw a1, 8(sp) - la a2, token_open_paren - call _token_compare - beqz a0, .Lcompile_identifier_call - - j .Lcompile_identifier_end - -.Lcompile_identifier_call: - lw a0, 20(sp) - lw a1, 16(sp) - call _compile_call - - j .Lcompile_identifier_end - -.Lcompile_identifier_assign: - call _build_expression - - la a0, instruction_addi - li a1, 4 - call write_out - - la a0, space - li a1, 1 - call write_out - - lw a0, 20(sp) - lw a1, 16(sp) - call write_out - - la a0, comma - li a1, 1 - call write_out - - la a0, register_a0 - li a1, 2 - call write_out - - la a0, comma - li a1, 1 - call write_out - - la a0, digit_zero - li a1, 1 - call write_out - - la a0, new_line - li a1, 1 - call write_out - - j .Lcompile_identifier_end - -.Lcompile_identifier_end: - # Epilogue. - lw ra, 28(sp) - lw s0, 24(sp) - addi sp, sp, 32 - ret - -.type _compile_var, @function -_compile_var: - # Prologue. - addi sp, sp, -32 - sw ra, 28(sp) - sw s0, 24(sp) - addi s0, sp, 32 - - # Variable name. - addi s1, s1, 3 - call _skip_spaces - call _read_token - sw s1, 20(sp) - sw a0, 16(sp) - add s1, s1, a0 - - # Skip the colon. - call _skip_spaces - call _read_token - add s1, s1, a0 - - call _skip_spaces - call _read_token - sw a0, 12(sp) - - addi a0, s1, 0 - lw a1, 12(sp) - la a2, token_open_square - call _token_compare - beqz a0, .Lcompile_var_array - - j .Lcompile_var_end - -.Lcompile_var_array: - call _skip_spaces - add s1, s1, 1 # Skip the opening square bracket. - - call _skip_spaces - call _read_token - sw a0, 8(sp) - - la a0, asm_type - li a1, ASM_TYPE_SIZE - call write_out - - lw a0, 20(sp) - lw a1, 16(sp) - call write_out - - la a0, asm_object - li a1, ASM_OBJECT_SIZE - call write_out - - la a0, asm_size - li a1, ASM_SIZE_SIZE - call write_out - - lw a0, 20(sp) - lw a1, 16(sp) - call write_out - - la a0, comma - li a1, 1 - call write_out - - addi a0, s1, 0 - lw a1, 8(sp) - call write_out - - la a0, new_line - li a1, 1 - call write_out - - lw a0, 20(sp) - lw a1, 16(sp) - call write_out - - la a0, colon - li a1, 1 - call write_out - - la a0, asm_zero - li a1, ASM_ZERO_SIZE - call write_out - - addi a0, s1, 0 - lw a1, 8(sp) - call write_out - - la a0, new_line - li a1, 1 - call write_out - - la a0, asm_global - li a1, ASM_GLOBAL_SIZE - call write_out - - lw a0, 20(sp) - lw a1, 16(sp) - call write_out - - la a0, new_line - li a1, 1 - call write_out - - lw a0, 8(sp) - add s1, s1, a0 - - call _skip_spaces - add s1, s1, 1 # Skip the closing square bracket. - - call _skip_spaces - call _read_token - - sw a0, 12(sp) - j .Lcompile_var_end - -.Lcompile_var_end: - lw a0, 12(sp) - add s1, s1, a0 - - # Epilogue. - lw ra, 28(sp) - lw s0, 24(sp) - addi sp, sp, 32 - ret - -.type _handle_token, @function -_handle_token: - # Prologue. - addi sp, sp, -32 - sw ra, 28(sp) - sw s0, 24(sp) - addi s0, sp, 32 - - sw a0, 20(sp) - - # Detect what token has been read. - addi a0, s1, 0 - lw a1, 20(sp) - la a2, token_begin - call _token_compare - beqz a0, .Lhandle_token_begin - - addi a0, s1, 0 - lw a1, 20(sp) - la a2, token_end - call _token_compare - beqz a0, .Lhandle_token_end - - addi a0, s1, 0 - lw a1, 20(sp) - la a2, token_import - call _token_compare - beqz a0, .Lhandle_token_import - - addi a0, s1, 0 - lw a1, 20(sp) - la a2, token_var - call _token_compare - beqz a0, .Lhandle_token_var - - # If the first symbol in the token is a character, assume an identifier. - addi a0, s1, 0 - lb a0, (a0) - call is_alpha - bnez a0, .Lhandle_token_identifier - - # Ignore the unknown token. - lw t0, 20(sp) - add s1, s1, t0 - j .Lhandle_token_return - -.Lhandle_token_begin: - call _compile_begin - j .Lhandle_token_return - -.Lhandle_token_end: - call _compile_end - j .Lhandle_token_return - -.Lhandle_token_import: - call _compile_import - j .Lhandle_token_return - -.Lhandle_token_var: - call _compile_var - j .Lhandle_token_return - -.Lhandle_token_identifier: - addi a0, s1, 0 - lw a1, 20(sp) - call _compile_identifier - j .Lhandle_token_return - -.Lhandle_token_return: - # Epilogue. - lw ra, 28(sp) - lw s0, 24(sp) - addi sp, sp, 32 - ret - -_start: - # Read the source from the standard input. - la a0, source_code - li a1, SOURCE_BUFFER_SIZE # Buffer size. - call read_file - - la s1, source_code # s1 = Source code position. - call compile - - # Call exit. - li a0, 0 # Use 0 return code. - call exit |