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。

1 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;
}

2 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~

执行

make && sudo make install

如果出现：
fel_lib.c:26:20: fatal error: libusb.h: No such file or directory

那需要安装libusb：

sudo apt-get install libusb-1.0-0-dev

如果出现

/bin/sh: 1: pkg-config: not found

安装：

sudo apt-get install build-essrntial pkg-config