How to using DMA fast copy uImage to DDR in uboot

Hi Qiuxin,

What is the size of your uImage and rootfs ?

Are you using "initramfs" ?

Also, please refer to the following TI wiki for u-boot optimization.

http://processors.wiki.ti.com/index.php/All_This_For_1_Second_Boot#Optimize_u-boot

Hi Titusrathinaraj Stalin 

uImage  2M

rootfs     16M

To rootfs,I using ramdisk. Thanks

hi Titusrathinaraj Stalin

Thanks, I want to know which modify uboot code to realize DMA fast copy way.

hi all

My boot parameters:

bootargs=mem=82m console=tty0 root=/dev/ram0 rw initrd=0xc3a00000,24M quiet
bootcmd=sf probe 0 30000000;sf read 0xc1700000 0x380000 0x80000;sf read 0xc0700000 0x80000 0x200000;sf read 0xc3a00000 0x1000000 0x1000000;bootm 0xc0700000

and 0xc1700000 is kernel-logo,0xc0700000 is kernel,0xc3a00000 is filesystems,which startup 26s .

I want to add DMA fast copy way to reduce this time. My board is TI  omapL138

Thanks.

hi Titusrathinaraj  Stalin

This src use nand flash about DMA. I want to use spi flash.they are different about read data form flash,which I copy failed. I use CONFIG_OMAP3_DMA,use drivers/dma/omap3_dma.c ,want to "sf read X X X" for DMA . I modify "drivers/spi/Davinci_spi.c" function "davinci_spi_read",but I can't modify

hi Titusrathinaraj  Stalin

Init function:

struct dma4_chan cfg;
omap3_dma_init();

/* config the channel */
if (0 != omap3_dma_get_conf_chan(0, &cfg))
{
printf("omap3_dma_get_conf_chan failed.\n ");
}

cfg.csdp = CSDP_DATA_TYPE_32BIT | CSDP_SRC_BURST_EN_64BYTES |
CSDP_DST_BURST_EN_64BYTES | CSDP_DST_ENDIAN_LOCK_ADAPT |
CSDP_DST_ENDIAN_LITTLE | CSDP_SRC_ENDIAN_LOCK_ADAPT |
CSDP_SRC_ENDIAN_LITTLE;
cfg.cfn = 1;
cfg.ccr = CCR_READ_PRIORITY_HIGH | CCR_SRC_AMODE_CONSTANT | CCR_DST_AMODE_POST_INC;
cfg.cicr = (1 << 5) | (1 << 11) | (1 << 10) | (1 << 8);
if (0 != omap3_dma_conf_chan(0, &cfg))
{
printf("omap3_dma_conf_chan failed.\n ");
}

hi Titusrathinaraj  Stalin

I want to use davinci_spi_read_dma replace davinci_spi_read about "sf read X X X ",but this function don't realize. 

static int davinci_spi_read_dma(struct spi_slave *slave, unsigned int len,
u8 *rxp, unsigned long flags)
{
struct davinci_spi_slave *ds = to_davinci_spi(slave);
unsigned int data1_reg_val;
printf("davinci_spi_read_dma start...\n");

/* enable CS hold, CS[n] and clear the data bits */
data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
(slave->cs << SPIDAT1_CSNR_SHIFT));

/* wait till TXFULL is deasserted */
while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
;

/* preload the TX buffer to avoid clock starvation */
writel(data1_reg_val, &ds->regs->dat1);

/* keep reading 1 byte until only 1 byte left */
/*while ((len--) > 1)
*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);*/

int nRes = 0;
nRes = omap3_dma_conf_transfer(0, ds, rxp, len);
rxp += len;
nRes = omap3_dma_start_transfer(0);
nRes = omap3_dma_wait_for_transfer(0);

/* clear CS hold when we reach the end */

if (flags & SPI_XFER_END)
data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);

/* read the last byte */
*rxp = davinci_spi_xfer_data(ds, data1_reg_val);

return 0;
}

Hi Qiuxin,

You have to understand the EDMA concept first and go for code walk through.

We don't have a DMA support for davinci PSP u-boot release so you have to write your own EDMA driver for davinci with the reference of OMAP3 EDMA3 driver.

I hope that need to change EDMA channel number and initialization could differ for davinci platform.

hi Titusrathinaraj  Stalin

 I watch to examples about spiedma.c in OMAPL_138 kernel,and I add this code to uboot. I use polling method,but in the function "Edma3ComplHandlerIsr", "isIPR = EDMA3GetIntrStatus(SOC_EDMA30CC_0_REGS)" return 0.

I only use readflash function,as follows:

/* ** This function reads data bytes from SPI Flash. */

static void ReadFromFlash(volatile u8 *pReadFlash, unsigned int len)

{    

unsigned int buffLength = len;    

unsigned int index = 0;    

unsigned char *writeFlash = (unsigned char *) malloc (sizeof(unsigned char) * len);

    /* Set the first 4 bytes of writeFlash with SPI Flash Read   ** Instruction Sequence.     */  

  memset(writeFlash, 0, sizeof(unsigned char) * len);    

writeFlash[0] = SPI_FLASH_READ;    

writeFlash[1] = SPI_FLASH_ADDR_MSB1;    

writeFlash[2] = SPI_FLASH_ADDR_MSB0;    

writeFlash[3] = SPI_FLASH_ADDR_LSB;

    /* Configure the PaRAM registers in EDMA for Transmission.*/    

SpiTxEdmaParamSet(EDMA3_CHA_SPI1_TX, EDMA3_CHA_SPI1_TX, writeFlash, buffLength);           

/* Registering Callback Function for Transmission. */    

cb_Fxn[EDMA3_CHA_SPI1_TX] = &callback;        

/* Configure the PaRAM registers in EDMA for Reception.*/    

SpiRxEdmaParamSet(EDMA3_CHA_SPI1_RX, EDMA3_CHA_SPI1_RX, pReadFlash, buffLength, TRUE);        

/* Registering Callback Function for Reception. */    

cb_Fxn[EDMA3_CHA_SPI1_RX] = &callback;        

/* Assert the CSHOLD line corresponding to the SPI Flash. */    

CSHoldAssert();        

/* Enable SPI controller to generate DMA events */    

SPIIntEnable(SOC_SPI_1_REGS, SPI_DMA_REQUEST_ENA_INT);        

/* Wait until both the flags are set to 1 in the callback function. */   

  while((0 == flagTx) || (0 == flagRx))    

{  

 Edma3ComplHandlerIsr();   

 Edma3CCErrHandlerIsr();

 }

 /* Disable SPI-EDMA Communication. */     SPIIntDisable(SOC_SPI_1_REGS, SPI_DMA_REQUEST_ENA_INT);

    flagTx = 0;     flagRx = 0;

  free(writeFlash);     

 pReadFlash += 4;  /*4是数据头,数据区*/    

/* Deassert the CSHOLD line corresponding to the SPI Flash. */    

CSHoldDeassert();   

printf("ReadFromFlash end\n");

}

for flagTx return 1,but flagRx return 0, what is the matter for this problem. Thanks!