diff options
Diffstat (limited to 'boot/common-boot.s')
| -rw-r--r-- | boot/common-boot.s | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/boot/common-boot.s b/boot/common-boot.s index 9c5ebc4..c6fcb98 100644 --- a/boot/common-boot.s +++ b/boot/common-boot.s @@ -1,4 +1,5 @@ -.global _is_alpha, _is_digit, _is_alnum, _is_upper, _is_lower, _write_out, _read_file, exit, _memcmp, _write_error +.global _is_alpha, _is_digit, _is_alnum, _is_upper, _is_lower +.global _write_out, _read_file, exit, _memcmp, _write_error, _put_char .section .rodata @@ -200,6 +201,29 @@ _read_file: ret # Terminates the program. a0 contains the return code. +.type _exit, @function exit: li a7, SYS_EXIT ecall + +# Writes a character from a0 into the standard output. +.type _put_char, @function +_put_char: + # Prologue + addi sp, sp, -16 + sw ra, 12(sp) + sw s0, 8(sp) + addi s0, sp, 16 + + sb a0, 4(sp) + li a0, STDOUT + addi a1, sp, 4 + li a2, 1 + li a7, SYS_WRITE + ecall + + # Epilogue. + lw ra, 12(sp) + lw s0, 8(sp) + add sp, sp, 16 + ret |