RosettaCodeData/Task/String-concatenation/RISC-V-Assembly/string-concatenation.asm
2026-04-30 12:34:36 -04:00

117 lines
3.7 KiB
NASM

# riscv assembly raspberry pico2 rp2350
# program concatstring.s
# connexion putty com3
/*********************************************/
/* CONSTANTES */
/********************************************/
/* for this file see risc-v task include a file */
.include "../../constantesRiscv.inc"
.equ BUFFERSIZE, 255
/*******************************************/
/* INITIALED DATAS */
/*******************************************/
.data
szMessStart: .asciz "Program riscv start.\r\n"
szMessEndOk: .asciz "Program riscv end OK.\r\n"
szCariageReturn: .asciz "\r\n"
szMessFinal: .asciz "The final string is \n"
szString1: .asciz "Hello "
szString2: .asciz " the world. \n"
szMessErrorSize: .asciz "Error : size final string too small\n"
.align 2
/*******************************************/
/* UNINITIALED DATA */
/*******************************************/
.bss
szFinalString: .skip BUFFERSIZE
.align 2
/**********************************************/
/* SECTION CODE */
/**********************************************/
.text
.global main
main:
call stdio_init_all # général init
1: # start loop connexion
li a0,0 # raz argument register
call tud_cdc_n_connected # waiting for USB connection
beqz a0,1b # return code = zero ?
la a0,szMessStart # message address
call writeString # display message
la a0,szString1 # adresse string 1
la a1,szString2 # adresse string 2
la a2,szFinalString # adresse string final
li a3,BUFFERSIZE # size area string final
call concatString # concat string
li t0,-1
beq a0,t0,100f # error ?
la a0,szMessFinal # message address
call writeString # display message
la a0,szFinalString
call writeString # display message
la a0,szCariageReturn # message address
call writeString # display message
la a0,szMessEndOk # message address
call writeString # display message
call getchar
100: # final loop
j 100b
/*********************************************/
/* add string to string */
/*********************************************/
/* a0 contains address String 1 */
/* a1 contains address String 2 */
/* a2 contains address String final */
/* a3 contains string final size */
concatString:
addi sp, sp, -4
sw ra, 0(sp)
li t0,0 # counter byte string 1
1:
add t1,a0,t0
lbu t2,(t1) # load byte string 1
add t1,a2,t0
sb t2,(t1) # store byte final string
beqz t2,2f # zero final ?
addi t0,t0,1 # no -> increment counter
bge t0,a3,99f # size maxi ?
j 1b # loop
2:
li t3, 0 # counter byte string 2
3:
add t4,a1,t3
lbu t5,(t4) # load byte string 2
add t1,a2,t0
sb t5,(t1) # store byte string final
beqz t5,100f # zero final ? -> end
addi t3,t3,1 # increment counter
addi t0,t0,1
bge t0,a3,99f # size maxi ?
j 3b # end loop
99:
la a0,szMessErrorSize
call writeString
li a0,-1 # return error
100:
lw ra, 0(sp)
addi sp, sp, 4
ret
/************************************/
/* file include Fonctions */
/***********************************/
/* for this file see risc-v task include a file */
.include "../../includeFunctions.s"