Support multiple targets (picozed and xu5)

[EmilioPeJu]

This change intends to support building rootfs for the xu5 board, the way to specify the target is with the variable PLATFORM which can be zynq or zynqmp. Here is a list of important facts to consider:

• With the newer kernel version, the FPGA is programmed using the FPGA manager interface (as the xdevcfg device is deprecated), the loading script is part of the FPGA repository. See PR
• This change expects the FPGA repository to be responsible for building boot.bin (wrapping fsbl and uboot) as well as the device tree blob. For Zynq US+, boot.bin should also include the PMU firmware and bl31 (Arm Trusted Firmware)
• We don't need Vivado/Vitis anymore for building this repository, we are using a more standard ARM toolchain (from ARM)
• PandABlocks-server should be built using the same toolchain to match the same libc, see PR
• There is a rootfs change needed here

Here is an example CONFIG used to test the changes:

ROOTFS_TOP = /dls_sw/work/panda2xu5/rootfs
TOOLCHAIN_ROOT = /dls_sw/targetOS/x-tools/gcc-10.2.1-glibc-2.31/$(COMPILER_PREFIX)
TAR_FILES = /dls_sw/work/panda2xu5/tar-files
PANDA_ROOT = /scratch/tmp/PandA-rootfs
PLATFORM = zynqmp

[Araneidae]

I have converted this to a draft pull request, as we'll have to merge all of the following in one big action:

1. The target independent build of PandABlocks-FPGA#33
2. This pull request, PandABlocks-rootfs#18
3. Possibly PandABlocks-server#10 (now merged)

I have converted PRs (1) and (2) above to draft status for now, as they definitely need to be merged at the same time.

[Araneidae]

Am I getting confused? Is this merge request really dependent on PandABlocks-FPGA#33?

[Araneidae]

Does this also need a CONFIG.example update?

[EmilioPeJu]

@Araneidae , Updating the kernel implies that the FPGA loading script should be changed. The xdevcfg device doesn't exist anymore (the associated driver is deprecated), and the new way is using the FPGA manager interface. The FPGA repo will likely need a change similar to the one shown below:

diff --git a/etc/load-panda-firmware b/etc/load-panda-firmware
index 45711560..14c476a2 100755
--- a/etc/load-panda-firmware
+++ b/etc/load-panda-firmware
@@ -33,6 +33,15 @@ configure_gpio_m0()
     echo $GPIO_M0 >/sys/class/gpio/unexport
 }

+load_fpga()
+{
+    local bitstream="$1"
+    # Set flags for loading full bitstream
+    echo 0 > /sys/class/fpga_manager/fpga0/flags
+    mkdir -p /lib/firmware
+    cp -f "$bitstream" /lib/firmware
+    echo "$(basename $bitstream)" > /sys/class/fpga_manager/fpga0/firmware
+}

 [ -e $carrier_firmware -a -e $slow_firmware ]  ||
     fail "Firmware not installed"
@@ -44,6 +53,6 @@ configure_gpio_m0  &&
 $check_ipmi  &&

 # If FMC passes then load the carrier firmware
-cat $carrier_firmware >/dev/xdevcfg  &&
+load_fpga $carrier_firmware  &&
 # Finally load the slow FPGA
 $slow_load <$slow_firmware

[Araneidae]

Ah. Ok, so these two merges still need to be synchronised. Think I've done everything I need to here?

[Araneidae]

All looks good to me!