commit 7bb36226a923999794652ad9cb96e7e0606cc76c
parent 6a76c5f0738626054d7b9f5e1b2fb41e0c253bea
Author: Matsuda Kenji <info@mtkn.jp>
Date: Sat, 2 Mar 2024 07:03:16 +0900
copy led blink to sram
Diffstat:
4 files changed, 170 insertions(+), 0 deletions(-)
diff --git a/ex1_sram/Makefile b/ex1_sram/Makefile
@@ -0,0 +1,36 @@
+AS = arm-none-eabi-as
+LD = arm-none-eabi-ld
+OBJCOPY = arm-none-eabi-objcopy
+BINCRC = ../tools/bincrc
+BIN2UF2 = ../tools/bin2uf2
+
+MCPU = -mcpu=cortex-m0plus
+ASFLAGS = $(MCPU)
+CFLAGS = $(MCPU) -ffreestanding -nostartfiles -O0 -fpic -mthumb -c
+LDFLAGS = --no-relax -nostdlib
+
+all: tools led.uf2
+
+clean:
+ rm -f *.o *.elf *.uf2 *.bin
+ cd ../tools && make clean
+
+.s.o:
+ $(AS) $(ASFLAGS) -o $@ $<
+
+led.elf: boot2.o main.o memmap.ld
+ $(LD) $(LDFLAGS) -o $@ -T memmap.ld boot2.o main.o
+
+led.bin: led.elf
+ $(OBJCOPY) -O binary led.elf $@
+
+led.uf2: led.bin
+ $(BINCRC) led.bin led_crc.bin
+ $(BIN2UF2) led_crc.bin $@
+
+flash: all
+ mount /dev/disk/by-label/RPI-RP2 /mnt
+ cp led.uf2 /mnt
+
+tools:
+ cd ../tools && make
diff --git a/ex1_sram/boot2.s b/ex1_sram/boot2.s
@@ -0,0 +1,46 @@
+.cpu cortex-m0plus
+.thumb
+
+ .section .boot2
+boot2:
+ // setup xip
+ ldr r3, rom_base
+ ldrh r0, [r3, #0x14] // rom_func_table
+ ldr r1, =('C' | 'X' << 8) // _flash_enter_cmd_xip()
+ ldrh r2, [r3, #0x18] // rom_table_lookup
+ blx r2
+ blx r0
+
+ // load main program to sram
+ ldr r0, =text_start
+ ldr r1, =text_size
+ mov r2, #0
+ ldr r3, sram_base
+copy:
+ cmp r1, r2
+ beq end
+ ldr r4, [r0, r2]
+ str r4, [r3, r2]
+ add r2, #4
+ b copy
+end:
+
+ // setup vector table
+ ldr r0, =vectors
+ ldr r1, m0plus_vtor
+ str r0, [r1, #0] // M0PLUS: VTOR
+ ldr r1, [r0, #4] // entry point
+ ldr r0, [r0, #0] // stack pointer
+ mov sp, r0
+ bx r1
+
+ .align 2
+rom_base:
+ .word 0x00000000
+sram_base:
+ .word 0x20000000
+m0plus_vtor:
+ .word 0xe0000000 + 0xed08
+literals:
+ .ltorg
+
diff --git a/ex1_sram/main.s b/ex1_sram/main.s
@@ -0,0 +1,62 @@
+.cpu cortex-m0plus
+.thumb
+
+ .section .vectors
+ .global vectors
+vectors:
+ .word 0x20040000 // initial SP
+ .word (reset+1) // entry point
+
+ .section .text
+reset:
+ // unreset gpio
+ mov r0, #1
+ lsl r0, r0, #5 // io_bank0
+ ldr r3, resets_base
+ ldr r1, atomic_clr
+ str r0, [r3, r1] // RESETS: RESET
+
+reset_chk:
+ ldr r1, [r3, #0x8] // RESETS: RESET_DONE
+ tst r0, r1
+ beq reset_chk
+
+ // set gpio functions
+ ldr r3, io_bank0_base
+ mov r0, #5 // sio
+ mov r1, #0xcc
+ str r0, [r3, r1] // IO_BANK0: GPIO25_CTRL
+
+ // enable gpio output
+ ldr r3, sio_base
+ mov r0, #1
+ lsl r0, r0, #25 // gpio25
+ str r0, [r3, #0x24] // SIO: GPIO_OE
+
+ // blink led on gpio25
+ ldr r4, sio_base
+ mov r5, r0
+loop:
+ str r5, [r4, #0x1c] // SIO_GPIO_OUT_XOR
+ bl delay
+ b loop
+
+delay:
+ mov r0, #1
+ lsl r0, r0, #20
+delay_loop:
+ sub r0, r0, #1
+ bne delay_loop
+ bx lr
+
+// literals
+ .align 2
+atomic_clr:
+ .word 0x00003000
+resets_base:
+ .word 0x4000c000
+io_bank0_base:
+ .word 0x40014000
+sio_base:
+ .word 0xd0000000
+
diff --git a/ex1_sram/memmap.ld b/ex1_sram/memmap.ld
@@ -0,0 +1,26 @@
+MEMORY
+{
+ FLASH(rx) : ORIGIN = 0x10000000, LENGTH = 2048k
+ SRAM(rwx) : ORIGIN = 0x20000000, LENGTH = 264k
+}
+
+SECTIONS
+{
+ .boot2 : {
+ *(.boot2)
+ . = 0x100;
+ } > FLASH
+
+ .vectors : {
+ *(.vectors)
+ . += SIZEOF(.vectors);
+ . = ALIGN(2);
+ text_start = .;
+ } > FLASH
+
+ .text : {
+ *(.text)
+ } > SRAM AT > FLASH
+ text_size = SIZEOF(.text);
+}
+
