Booting using "Direct Kernel Boot" for PolarFire SoC & skipping u-boot
entirely is probably not advisable, but it does at least show signs of
life. Recent Linux kernel versions make use of peripherals that are
missing definitions in QEMU and lead to kernel panics. These issues
almost certain rear their head for other methods of booting, but I was
unable to figure out a suitable HSS version that is recent enough to
support these peripherals & works with QEMU.
With these peripherals added, booting a kernel with the following hangs
hangs waiting for the system controller's hwrng, but the kernel no
longer panics. With the Linux driver for hwrng disabled, it boots to
console.
qemu-system-riscv64 -M microchip-icicle-kit \
-m 2G -smp 5 \
-kernel $(vmlinux_bin) \
-dtb $(dtb)\
-initrd $(initramfs) \
-display none -serial null \
-serial stdio
More peripherals are added than strictly required to fix the panics in
the hopes of avoiding a replication of this problem in the future.
Some of the peripherals which are in the device tree for recent kernels
are implemented in the FPGA fabric. The eMMC/SD mux, which exists as
an unimplemented device is replaced by a wider entry. This updated
entry covers both the mux & the remainder of the FPGA fabric connected
to the MSS using Fabric Interrconnect (FIC) 3.
Link: https://github.com/polarfire-soc/icicle-kit-reference-design#fabric-memory-map
Link: https://ww1.microchip.com/downloads/aemDocuments/documents/FPGA/ProductDocuments/SupportingCollateral/V1_4_Register_Map.zip
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220813135127.2971754-1-mail@conchuod.ie>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
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