WhyCan Forum(哇酷开发者社区)

官网上是这样的
sunxi-fel增加对16M以上Flash的支持

由于SPI flash 的地址是24bit，也就是最大16M 地址空间，所以对于32M flash，需要增加bank切换支持。
uboot中有 CONFIG_SPI_FLASH_BAR 选项可以使能bank切换。
但是sunxi-fel中尚未支持，所以下载的时候超出16M会循环覆盖掉。
这里介绍对sunxi-fel增加16M以上flash支持的方法。
u-boot的支持
drivers/mtd/spi/spi_flash.c
static int write_bar(struct spi_flash *flash, u32 offset)
{
     u8 cmd, bank_sel;
     int ret;

     bank_sel = offset / (SPI_FLASH_16MB_BOUN << flash->shift);
     if (bank_sel == flash->bank_curr)
         goto bar_end;

     cmd = flash->bank_write_cmd;
     ret = spi_flash_write_common(flash, &cmd, 1, &bank_sel, 1);
     if (ret < 0) {
         debug("SF: fail to write bank register\n");
         return ret;
     }

bar_end:
     flash->bank_curr = bank_sel;
     return flash->bank_curr;
}
sunxi-fel的支持
fel-spiflash.c
#define CMD_WRITE_ENABLE 0x06
#define SPI_FLASH_16MB_BOUN  0x1000000
# define CMD_BANKADDR_BRWR              0x17        //only SPANSION flash use it
# define CMD_BANKADDR_BRRD              0x16
# define CMD_EXTNADDR_WREAR             0xC5
# define CMD_EXTNADDR_RDEAR             0xC8
size_t bank_curr = 0;

void aw_fel_spiflash_write_helper(feldev_handle *dev,
                 uint32_t offset, void *buf, size_t len,
                 size_t erase_size, uint8_t erase_cmd,
                 size_t program_size, uint8_t program_cmd)
{
     uint8_t *buf8 = (uint8_t *)buf;
     size_t max_chunk_size = dev->soc_info->scratch_addr - dev->soc_info->spl_addr;
     size_t cmd_idx, bank_sel;

     if (max_chunk_size > 0x1000)
         max_chunk_size = 0x1000;
     uint8_t *cmdbuf = malloc(max_chunk_size);
     cmd_idx = 0;

     prepare_spi_batch_data_transfer(dev, dev->soc_info->spl_addr);
     //add bank support
     {
     cmd_idx = 0;
     bank_sel = offset /SPI_FLASH_16MB_BOUN;
     if (bank_sel == bank_curr)
         goto bar_end;

     /* Emit write enable command */
     cmdbuf[cmd_idx++] = 0;
     cmdbuf[cmd_idx++] = 1;
     cmdbuf[cmd_idx++] = CMD_WRITE_ENABLE;
     /* Emit write bank */
     cmdbuf[cmd_idx++] = 0;
     cmdbuf[cmd_idx++] = 2;
     cmdbuf[cmd_idx++] = CMD_EXTNADDR_WREAR;
     cmdbuf[cmd_idx++] = offset >> 24;
     /* Emit wait for completion */
     cmdbuf[cmd_idx++] = 0xFF;
     cmdbuf[cmd_idx++] = 0xFF;
     /* Emit the end marker */
     cmdbuf[cmd_idx++] = 0;
     cmdbuf[cmd_idx++] = 0;
     aw_fel_write(dev, cmdbuf, dev->soc_info->spl_addr, cmd_idx);
     aw_fel_remotefunc_execute(dev, NULL);
     bar_end:
         bank_curr = bank_sel;
     }

     cmd_idx = 0;
重新编译sunxi-fel后就可以烧录32M flash了~