/* Copyright (c) 2015 Ivan Grokhotkov. All rights reserved. 
 * This file is part of eboot bootloader.
 *
 * Redistribution and use is permitted according to the conditions of the
 * 3-clause BSD license to be found in the LICENSE file.
 */


#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include "eboot.h"
#include "eboot_command.h"
extern void* flashchip;

#define SWRST do { (*((volatile uint32_t*) 0x60000700)) |= 0x80000000; } while(0);


int load_app_from_flash_raw(const uint32_t flash_addr)
{
    image_header_t image_header;
    uint32_t pos = flash_addr + APP_START_OFFSET;

    if (SPIRead(pos, &image_header, sizeof(image_header))) {
        return 1;
    }
    pos += sizeof(image_header);
    

    for (uint32_t section_index = 0;
        section_index < image_header.num_segments; 
        ++section_index)
    {
        section_header_t section_header = {0};
        if (SPIRead(pos, &section_header, sizeof(section_header))) {
            return 2;
        }
        pos += sizeof(section_header);

        const uint32_t address = section_header.address;

        bool load = false;

        if (address < 0x40000000) {
            load = true;
        }

        if (address >= 0x40100000 && address < 0x40108000) {
            load = true;
        }

        if (address >= 0x60000000) {
            load = true;
        }

        if (!load) {
            pos += section_header.size;
            continue;
        }

        if (SPIRead(pos, (void*)address, section_header.size))
            return 3;

        pos += section_header.size;
    }

    register uint32_t sp asm("a1") = 0x3ffffff0;
    register uint32_t pc asm("a3") = image_header.entry;
    __asm__  __volatile__ ("jx a3");

    return 0;
}



int erase(const uint32_t start, const uint32_t size)
{
    if (start & (FLASH_SECTOR_SIZE - 1) != 0) {
        return 1;
    }

    const uint32_t sectors_per_block = FLASH_BLOCK_SIZE / FLASH_SECTOR_SIZE;
    uint32_t current_sector = start / FLASH_SECTOR_SIZE;
    uint32_t sector_count = (size + FLASH_SECTOR_SIZE - 1) / FLASH_SECTOR_SIZE;
    const uint32_t end = current_sector + sector_count;

    for (; current_sector < end && (current_sector & (sectors_per_block-1)); 
        ++current_sector, --sector_count) {
        if (SPIEraseSector(current_sector)) {
            return 2;
        }
    }

    for (;current_sector + sectors_per_block <= end; 
        current_sector += sectors_per_block, 
        sector_count -= sectors_per_block) {
        if (SPIEraseBlock(current_sector / sectors_per_block)) {
            return 3;
        }
    }

    for (; current_sector < end; 
        ++current_sector, --sector_count) {
        if (SPIEraseSector(current_sector)) {
            return 4;
        }
    }

    return 0;
}

int copy_raw(const uint32_t src_addr, 
             const uint32_t dst_addr, 
             const uint32_t size)
{
    // require regions to be aligned
    if (src_addr & 0xfff != 0 ||
        dst_addr & 0xfff != 0) {
        return 1;
    }

    if (erase(dst_addr, size)) {
        return 2;
    }

    const uint32_t buffer_size = 4096;
    uint8_t buffer[buffer_size];

    const uint32_t end = src_addr + size;
    uint32_t saddr = src_addr;
    uint32_t daddr = dst_addr;
    uint32_t left = size;
    while (saddr < end) {
        uint32_t will_copy = (left < buffer_size) ? left : buffer_size;
        if (SPIRead(saddr, buffer, will_copy)) {
            return 3;
        }
        if (SPIWrite(daddr, buffer, will_copy)) {
            return 4;
        }
        saddr += will_copy;
        daddr += will_copy;
        left  -= will_copy;
    }

    return 0;
}



void main()
{
    int res;
    struct eboot_command cmd;

    eboot_command_read(&cmd);

    if (cmd.action == ACTION_COPY_RAW) {
        res = copy_raw(cmd.args[0], cmd.args[1], cmd.args[2]);
        if (res == 0) {
            cmd.action = ACTION_LOAD_APP;
        }
    }

    if (cmd.action == ACTION_LOAD_APP) {
        res = load_app_from_flash_raw(0);
    }

    if (res) {
        ets_putc('\n');
        ets_putc('#');
        ets_putc('0' + res);
        ets_putc('\n');
        SWRST;
    }

    while(true){}
}