59 lines
2 KiB
NASM
59 lines
2 KiB
NASM
# riscv assembly raspberry pico2
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# program hello.s
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# connexion putty com3
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/*********************************************/
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/* CONSTANTES */
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/********************************************/
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/*******************************************/
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/* INITIALED DATAS */
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/*******************************************/
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.data
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szMessHello: .asciz "Hello world.\r\n"
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szMessStart: .asciz "Program riscv start.\r\n"
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/*******************************************/
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/* UNINITIALED DATA */
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/*******************************************/
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.bss
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.align 2
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/**********************************************/
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/* SECTION CODE */
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/**********************************************/
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.text
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.global main
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main:
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call stdio_init_all # général init
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1: # start loop connexion
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li a0,0 # raz argument register
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call tud_cdc_n_connected
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beqz a0,1b # return code = zero ?
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la a0,szMessStart # message address
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call writeString # display message
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la a0,szMessHello # message address
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call writeString # display message
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100: # final loop
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j 100b
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/************************************/
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/* string write on connexion usb */
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/***********************************/
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/* a0 String address */
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writeString: # INFO: writeString
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addi sp, sp, -8 # save registers on stack
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sw ra, 0(sp)
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sw s0, 4(sp)
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mv s0,a0 # move address
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1:
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lbu a0,(s0) # load one character
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beqz a0,100f # end if zero
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call putchar # character write
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add s0,s0,1 # increment address
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j 1b # and loop
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100: # end function
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lw ra, 0(sp) # restaur registers
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lw s0, 4(sp)
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addi sp, sp, 8
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ret
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