Hi John Paul,

Am 02.02.21 um 20:12 schrieb John Paul Morrison:
> I'm just starting to look at fashrom to see how to read/update SPI
> flash on a PCIe card
>
> lspci -d 1106:3483
> 01:00.0 USB controller: VIA Technologies, Inc. VL805 USB 3.0 Host
> Controller (rev 01)
>
> There isn't much from Via but the chipset is used in the Raspberry Pi
> 4 and the Pi firmware provides a flash tool vl805 (no source code of
> course!)

I have a working flashrom driver for that host controller, but I need
testers. Back when I wrote the driver at the end of 2019 I didn't even
have a Raspberry Pi 4 and was just reverse engineering the behaviour
from traces with some help from clever on IRC.


> I can run it on Intel with Qemu - unfortunately for me the tool is
> hard coded for a different SPI flash chip (and in later Pi hardware
> seems to have been moved/removed)
>
> Inspecting the board and related datasheets (VL800) the chipset has an
> SPI interface for firmware, and it can be used for PCI BIOS
> apparently.  The actual SPI chip varies from board to board - mine is
> FM25Q04 from the data sheet ID=A112. Raspberry Pi seems to use
> W25X10BV  based on the ID EF10
>
> Are there any simple examples of accessing SPI on PCIe cards?
>
> sorry for the long post - I've included a bit  more info on what I
> could find on the chip

Thanks.

I really should update the VL805 patch against current flashrom and
submit it.

>
> thanks
>
> John Paul

Regards,
Carl-Daniel


> Other info on the chip:
>
> I can  read the firmware version easily:
>
> sudo lspci -d 1106:3483 -xxx | awk '/^50:/ { print "VL805 FW version:
> " $5 $4 $3 $2 }'
>
> I can use strace to see what vl805 doing - I can make out some SPI
> commands - here it reads the SPI flash chip ID:
> openat(AT_FDCWD, "/sys/bus/pci/devices/0000:01:00.0/config", O_RDWR) = 4
> (bunch of reads/writes)
> pread64(4, "\22\241\22\241", 4, 124)    = 4                          
> write(1, "R Rx_REG0 a112a112\n", 19)    = 19
>
>
> sudo ~/vl805/vl805 -d
> VL805 FW version: 00013600
> W CHIP_SEL 00000001
> R PCI_WB_EN ffffffff
> W PCI_WB_EN ffffff01
> R STOP_POLLING 00000001
> W STOP_POLLING 00000001
> W CTRL_REG 000005a0
> W CLK_DIV 0000000a
> W CHIP_SEL 00000000
> W Tx_REG0 90000000
> W CTRL_REG 000005c0
> R Rx_REG0 a112a112
> W CHIP_SEL 00000001
> * flash ID mismatch - found a112, expected 0000ef10
>
> I was able to find a Windows based firmware updater which supports
> about 20 different SPI chips - people have reported adding new
> chipsets, looks like I have to add mine as well. 
> The flash tool runs under wine but it can't read anything - will have
> to find a fix or run in a vm.
>
>
> Via SpiFlash.ini:
> [MX25L512]
> FlashID=C22010
> ReadID=9F
> WriteEnable=06
> WriteStatus=01
> ChipErase=60
> ReadData=03
> ReadStatus=05
> PageProgram=02
> ClockRate=32
> PageSize=100
>
> Raspberry Pi 4 ?
> [W25X10BV]
> FlashID=EF10
> ReadID=90000000
> WriteEnable=06
> WriteStatus=01
> ChipErase=C7
> ReadData=03
> ReadStatus=05
> PageProgram=02
> ClockRate=32
> PageSize=10