oops, forgot to add microloader

CC := arm-none-eabi-gcc

AS := arm-none-eabi-as

LD := arm-none-eabi-gcc

OBJCOPY := arm-none-eabi-objcopy

CFLAGS := -std=gnu99 -Os -mthumb -mcpu=cortex-a9 -fno-builtin-printf -fno-strict-aliasing -fno-builtin-memcpy -mno-unaligned-access -DPRINTF_DISABLE_SUPPORT_FLOAT=1

LDFLAGS := -T linker.x -nodefaultlibs -nostdlib

BUILD_DIR := ./build

TARGET := payload

C_SRC = main.c

ASM_SRC = start.S

OBJ = $(C_SRC:%.c=$(BUILD_DIR)/%.o) $(ASM_SRC:%.S=$(BUILD_DIR)/%.o)

DEP = $(OBJ:%.o=%.d)

$(BUILD_DIR)/$(TARGET).bin: $(BUILD_DIR)/$(TARGET).elf

	$(OBJCOPY) -O binary $^ $@

$(BUILD_DIR)/$(TARGET).elf: $(OBJ)

	$(LD) -o $@ $^ $(LDFLAGS)

-include $(DEP)

$(BUILD_DIR)/%.o: %.c

	mkdir -p $(@D)

	$(CC) -MMD -c -o $@ $< $(CFLAGS)

$(BUILD_DIR)/%.o: %.S

	mkdir -p $(@D)

	$(AS) -o $@ $<

clean:

	-rm -rf $(BUILD_DIR)

OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")

OUTPUT_ARCH(arm)

ENTRY(start)

SECTIONS

{

  . = 0x4BD5C100;

  .text     : { *(.text.start) *(.text   .text.*   .gnu.linkonce.t.*) }

  .rodata   : { *(.rodata .rodata.* .gnu.linkonce.r.*) }

  .data     : { *(.data   .data.*   .gnu.linkonce.d.*) }

  .bss      : { *(.bss    .bss.*    .gnu.linkonce.b.*) *(COMMON) }

  /DISCARD/ : { *(.interp) *(.dynsym) *(.dynstr) *(.hash) *(.dynamic) *(.comment) }

}

#include <inttypes.h>

#include <stddef.h>

#include "../lk-payload/common.h"

void low_uart_put(int ch) {

    volatile uint32_t *uart_reg0 = (volatile uint32_t*)0x11002014;

    volatile uint32_t *uart_reg1 = (volatile uint32_t*)0x11002000;

    while ( !((*uart_reg0) & 0x20) )

    {}

    *uart_reg1 = ch;

}

int putchar(int character) {

    if (character == '\n')

        low_uart_put('\r');

    low_uart_put(character);

    return character;

}

int puts(const char *line) {

    for (const char *c = line; *c; ++c) {

        putchar(*c);

    }

    putchar('\n');

    return 0;

}

int main() {

    puts("microloader by xyz. Copyright 2019.");

    struct device_t *dev = (void*)get_device();

    uint32_t *dst = (void*)PAYLOAD_DST;

    size_t ret = dev->read(dev, PAYLOAD_SRC, dst, PAYLOAD_SIZE, BOOT0_PART); // boot0 partition, read 2 megabytes

    cache_clean(dst, PAYLOAD_SIZE);

    // Jump to the payload

    void (*jump)(void) = (void*)dst;

    puts("Jump to the payload");

    jump();

    puts("Something went horribly wrong!");

    while (1) {

    }

}

.syntax unified

.code 32

.global start

.section .text.start

start:

    mov sp, #0x42000000

    blx main