TivaFlash.cxx

 
#include "TivaFlash.hxx"
 
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/flash.h"
 
ssize_t TivaFlash::read(File *f, void *buf, size_t size)
{
    if ((uint32_t)f->offset >= len_)
    {
        size = 0;
    }
    else
    {
        size = std::min(size, len_ - (size_t)f->offset);
    }
    memcpy(buf, base_ + f->offset, size);
    f->offset += size;
    return size;
}
 
static uint32_t write_buf[32];
 
ssize_t TivaFlash::write(File *f, const void *buf, size_t size)
{
    // Do not write beyond the end of the file.
    if ((uint32_t)f->offset >= len_)
    {
        return 0;
    }
    else
    {
        size = std::min(size, len_ - (size_t)f->offset);
    }
    uint32_t write_address = reinterpret_cast<uint32_t>(base_) + f->offset;
    const uint8_t *read_buf = static_cast<const uint8_t *>(buf);
    uint32_t end_address = write_address + size;
    ssize_t ret = 0;
    while (write_address < end_address)
    {
        HASSERT((write_address & 3) == 0);
        // If we are at the start of a page, let's erase the page.
        if (!(write_address & subpage_mask()))
        {
            MAP_FlashErase(reinterpret_cast<uint32_t>(write_address));
        }
        uint32_t current_end_address = end_address;
        // Checks if we are trying to write more than one page.
        if ((current_end_address & write_page_mask()) !=
            (write_address & write_page_mask()))
        {
            // Stops writing at the end of the current page.
            current_end_address =
                (write_address + write_page_size() - 1) & write_page_mask();
        }
        uint32_t current_len = current_end_address - write_address;
        HASSERT(current_len <= sizeof(write_buf));
        memcpy(write_buf, read_buf, current_len);
        if (MAP_FlashProgram(write_buf, write_address, (current_len + 3) & ~3) < 0)
        {
            return -EIO;
        }
        write_address += current_len;
        read_buf += current_len;
        f->offset += current_len;
        ret += current_len;
    }
    return ret;
}