掌機 - GKD Pixel - Assembly - LED

LCD背光連接到PC-14


Output


Data


main.s

    .extern _start
    .set noreorder

    .equiv LCD_BL, 14
    .equiv DELAY, 0x100000

    .equiv PA, 0xb0010000
    .equiv PB, 0xb0011000
    .equiv PC, 0xb0012000
    .equiv PD, 0xb0013000

    .equiv PXPAT1, 0x0030
    .equiv PXPAT0, 0x0040

    .text
    .ascii "LPSM"

    .rept 2044
    .byte 0
    .endr

_start:
    li $9, 0
    li $8, PA + PXPAT1
    sw $9, 0($8)
    li $8, PB + PXPAT1
    sw $9, 0($8)
    li $8, PC + PXPAT1
    sw $9, 0($8)
    li $8, PD + PXPAT1
    sw $9, 0($8)

    li $9, 0xffffffff
    li $8, PA + PXPAT0
    sw $9, 0($8)
    li $8, PB + PXPAT0
    sw $9, 0($8)
    li $8, PC + PXPAT0
    sw $9, 0($8)
    li $8, PD + PXPAT0
    sw $9, 0($8)

loop:
    xor $9, (1 << LCD_BL)
    li $8, PC + PXPAT0
    sw $9, 0($8)

    li $8, DELAY
0:
    addi $8, $8, -1
    bnez $8, 0b
    nop

    b loop
    nop

main.ld

OUTPUT_FORMAT("elf32-tradlittlemips", "elf32-tradbigmips", "elf32-tradlittlemips")
OUTPUT_ARCH(mips)
ENTRY(_start)

SECTIONS
{
    . = 0;
    .text : { *(.text) }
    .data : { *(.data) }
    .bss  : { *(.bss)  }
}

Makefile

all:
	mipsel-linux-gnu-as -o main.o main.s
	mipsel-linux-gnu-ld -T main.ld -o main.elf main.o
	mipsel-linux-gnu-objcopy -O binary main.elf main.bin

flash:
	sudo dd if=main.bin of=/dev/sdX bs=1K seek=17

clean:
	rm -rf main.bin main.o main.elf

編譯、燒錄到MicroSD

$ make
    mipsel-linux-gnu-as -o main.o main.s
    mipsel-linux-gnu-ld -T main.ld -o main.elf main.o
    mipsel-linux-gnu-objcopy -O binary main.elf main.bin

$ make flash
    sudo dd if=main.bin of=/dev/sdX bs=1K seek=17
    1+1 records in
    1+1 records out
    1232 bytes (1.2 kB, 1.2 KiB) copied, 0.023186 s, 53.1 kB/s

完成