PMP V >> Assembly
UART
main.s
.equiv zero, $0 .equiv at, $1 .equiv v0, $2 .equiv v1, $3 .equiv a0, $4 .equiv a1, $5 .equiv a2, $6 .equiv a3, $7 .equiv t0, $8 .equiv t1, $9 .equiv t2, $10 .equiv t3, $11 .equiv t4, $12 .equiv t5, $13 .equiv t6, $14 .equiv t7, $15 .equiv s0, $16 .equiv s1, $17 .equiv s2, $18 .equiv s3, $19 .equiv s4, $20 .equiv s5, $21 .equiv s6, $22 .equiv s7, $23 .equiv t8, $24 .equiv t9, $25 .equiv k0, $26 .equiv k1, $27 .equiv gp, $28 .equiv sp, $29 .equiv fp, $30 .equiv ra, $31 .equiv CLKGR, 0xb0000020 .equiv URBR0, 0xb0030000 .equiv UDLLR0, 0xb0030000 .equiv UDLHR0, 0xb0030004 .equiv UIER0, 0xb0030004 .equiv UFCR0, 0xb0030008 .equiv ULCR0, 0xb003000c .equiv ULSR0, 0xb0030014 .equiv ISR0, 0xb0030020 .equiv PCFUNS, 0xb0010244 .equiv PCTRGC, 0xb0010278 .equiv PCSELS, 0xb0010254 .globl _start .set noreorder .text .ifdef STAGE2 .word 0x555555ff .word 0x55555555 .byte 0xff .byte 0xff .byte 0xff .byte 0x00 .endif _start: nop li v0, 0x00400004 # disable interrupt mtc0 v0, $12 li v1, 0x00800000 # clear cause content mtc0 v1, $13 li sp, 0x80004000 uart_init: li v0, 0x1000 sw v0, PCFUNS sw v0, PCTRGC sw v0, PCSELS lw v0, CLKGR li v1, 0xfffffffe and v0, v1 sw v0, CLKGR sb zero, UIER0 li v0, 0xef sb v0, UFCR0 li v0, 0xfc sb v0, ISR0 li v0, 0x03 sb v0, ULCR0 lbu v0, ULCR0 ori v0, 0x80 sb v0, ULCR0 sb zero, UDLHR0 li v0, 0x0d sb v0, UDLLR0 lbu v0, ULCR0 li v1, 0x7f and v0, v1 sb v0, ULCR0 li v0, 0x17 sb v0, UFCR0 jal delay li a0, 100 jal uart_char li a0, 'A' end: b end uart_char: sb a0, URBR0 0: lbu v0, ULSR0 andi v0, 0x60 li v1, 0x60 bne v0, v1, 0b nop jr ra nop delay: li v0, 180 mul a0, v0 0: bnez a0, 0b addiu a0, -1 jr ra nop
main.ld
OUTPUT_ARCH(mips)
ENTRY(_start)
MEMORY
{
low8k : ORIGIN = 0x80000000 , LENGTH = 0x2000
high8k : ORIGIN = 0x80002000 , LENGTH = 0x2000
}
SECTIONS
{
.text : {
*(.text.1)
*(.text.0)
} > low8k
.data : {
. = ALIGN(4);
*(.rodata*) *(.data*) *(.scommon*) *(.reginfo*)
} > low8k
.bss : {
. = ALIGN(4);
_bss_start = ABSOLUTE(.);
*(.sbss*) *(.bss*)
. = ALIGN(4);
_bss_end = ABSOLUTE(.);
} > high8k
__stack = 0x80004000;
}
Makefile
all: mipsel-linux-as -o main.o main.s --defsym=STAGE1=1 mipsel-linux-ld -T main.ld -o main.elf main.o mipsel-linux-objcopy -O binary main.elf stage1.bin clean: rm -rf main.o main.elf main.bin stage1.bin
編譯
$ cd $ wget https://github.com/steward-fu/pmp-v/releases/download/v1.0/rs90-toolchain-2019.04.30.tar $ tar xvf rs90-toolchain-2019.04.30.tar $ sudo mv rs90-toolchain /opt/ $ export PATH=$PATH:/opt/rs90-toolchain/usr/bin $ make
接著進入燒錄模式(按下B插入USB)，再使用jzboot燒錄stage1.bin就可以
