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spiread.md

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spiread

spiread - read data by bytes from sunxi spi-flash to ram, avail in uboot shell cmd for next linux loading

USAGE

spiread HEX_DST DEC_OFFSET DEC_BYTES

  • HEX_DST - mem addr always used as hex!
  • OFFSET - offset in bytes from begin of flash
  • BYTES - how many bytes read from flash to mem by addr HEX_DST

EXTENSIONS

  • spiread.h - hex_dst hex_offset hex_bytes
  • spiread.d - hex_dst dec_offset dec_bytes
  • spiread.dh - hex_dst dec_offset hex_bytes
  • spiread.hd - hex_dst hex_offset dec_bytes

NOTE

spiread.d work same as spiread - offset and bytes in dec

EXAMPLES

read 1048576 bytes from begin spi-flash to 0x42000000 addr

=> spiread 0x42000000 0 1048576
SPI readed 1048576 bytes from 0 offset, time 0.560

read 1048576 bytes from hex A0000 offset to 0x42000000 addr

=> spiread.hd 0x42000000 A0000 1048576
SPI readed 1048576 bytes from 655360 offset, time 0.560

same but all in dec offset and bytes

=> spiread.d 0x42000000 655360 1048576
SPI readed 1048576 bytes from 655360 offset, time 0.560

same but all in hex

=> spiread.h 0x42000000 A0000 FFFFF
SPI readed 1048576 bytes from 655360 offset, time 0.560

read full 8M and 16M flash to 0x00000000 addr

=> spiread.h 0 0 800000
SPI readed 8388608 bytes from 0 offset, time 5.363
=> spiread.h 0 0 1000000
SPI readed 16777216 bytes from 0 offset, time 10.676

check readed 0x40 bytes uboot-header data from spi-flash

=> mw.b 0 FF 40
=> spiread.h 0 8000 40 
SPI readed 64 bytes from 32768 offset, time 0.000
=> md.b 0 40
00000000: 27 05 19 56 2d d0 13 d2 58 d5 22 de 00 06 92 2e    '..V-...X.".....
00000010: 4a 00 00 00 00 00 00 00 96 ab 7d 10 11 02 05 00    J.........}.....
00000020: 55 2d 42 6f 6f 74 20 32 30 31 37 2e 30 31 2d 68    U-Boot 2017.01-h
00000030: 79 70 68 6f 70 20 6d 69 5a 79 20 66 6f 72 20 73    yphop miZy for s

HOWTO LOAD LINUX

add some strings like this to uboot script for loading linux from spi-flash

spiread.hd ${kernel_addr_r} ${kernel_offset} ${kernel_size}
spiread.hd ${ramdisk_addr_r} ${ramdisk_offset} ${ramdisk_size}
spiread.hd ${fdt_addr_r} ${fdt_offset} ${fdt_size}
bootm ${kernel_addr_r} ${ramdisk_addr_r} ${fdt_addr_r}

be sure all reuired env vars have actual values!!!

READ IMAGES NOTE

if u dont know real kernel_size or ramdisk_size or fdt_size u can read some extra data (for example read full mtd part which contain it), because image packed by mkimage and actual image size already store in mkimage header, and they must unpacked corretly!

SPEED

sunxi spi-flash reading speed is about 1.5 - 1.78 Mb/s

1048576/0.560 = 1872457 b/s
16777216/10.676 = 1571489 b/s
1/0.560 = 1.78571428571429
16/10.676 = 1.4986886474335

spi bus work on fixed 24Mhz, maybe we can improve speed later