feat(boards/premier-p550): add SiFive HiFive Premier P550

README.md

@@ -27,6 +27,7 @@ Rootless cross-compilation of Gentoo stages using crossdev and hakoniwa
 | odroid-m1s | aarch64 | mainline v7.0 | TFA + U-Boot + rkbin | `-O3 -mcpu=cortex-a55` | testing |
 | odroid-m2 | aarch64 | mainline v7.0 | TFA + U-Boot + rkbin | `-O3 -mcpu=cortex-a76.cortex-a55` | testing |
 | pentium-mmx | i586 | mainline v6.12 | BIOS (no firmware) | `-O2 -march=pentium-mmx` | testing |
+| premier-p550 | riscv64 | mainline v7.2-rc1 | vendor QSPI (OpenSBI + U-Boot) + extlinux | `-O3 -march=rv64gc_zba_zbb` | testing |
 
 ## CLI
 

boards/premier-p550/README.md

@@ -0,0 +1,106 @@
+# SiFive HiFive Premier P550 (ESWIN EIC7700X)
+
+Quad-core SiFive P550 (rv64gc + zba + zbb, **no V**) — `eic7700-hifive-premier-p550.dts` upstream since Linux 6.18; ethernet/MMC since 6.19.
+
+## Boot chain
+
+```
+Boot ROM (on-die)
+  -> reads bootchain from QSPI NOR (pre-flashed by vendor)
+     ddr_fw.bin + second_boot_fw.bin + OpenSBI v1.6 + u-boot 2024.01-EIC7X
+  -> u-boot `bootflow scan -b` over boot_targets=mmc1 usb nvme0 ahci mmc0
+     1. /extlinux/extlinux.conf   ← we ship this; first match wins
+     2. /boot.scr.uimg
+     3. /EFI/BOOT/bootriscv64.efi
+```
+
+extlinux is the primary path: vendor u-boot's bootmeth order tries it
+first, and its handler env-expands `${ram_size}` (set by the vendor
+`dram_init()`) into the kernel cmdline.  `mem=${ram_size}G` comes from
+the vendor SDK's own extlinux.conf; mainline-DTB boots without it fault
+in `paging_init` (`__memset`, cause=7 store access fault on
+PMP-protected memory), so we keep it.  The mainline
+`eic7700-hifive-premier-p550.dts` skeleton has no `/memory` or
+`/reserved-memory` nodes and relies on u-boot's fixups alone.
+
+**Our image does not touch QSPI.**  The vendor bring-up chain in QSPI is
+re-used as-is.  We only supply the OS storage media — a single GPT image
+with `bootfs` (`Image`, DTB, `extlinux/extlinux.conf`) and `rootfs`.
+
+If QSPI is damaged, see `boards/premier-p550-full/` (future) — that
+variant rebuilds the QSPI chain from `eswincomputing/u-boot`,
+`eswincomputing/opensbi`, and the two closed firmware blobs from
+`sifiveinc/hifive-premier-p550-tools`.
+
+## Flash
+
+The single `gentoo-linux-premier-p550_dev-sdcard-<timestamp>.img.xz`
+works on any medium u-boot's `boot_targets` covers.
+
+```sh
+xzcat gentoo-linux-premier-p550_dev-sdcard-<timestamp>.img.xz \
+    | sudo dd of=/dev/<target> bs=4M status=progress conv=fsync
+```
+
+`/dev/<target>` examples:
+- microSD on a host card reader: `/dev/sdX` (whichever your reader maps to)
+- NVMe (after removing the M.2 and plugging into a USB-NVMe enclosure): `/dev/sdX`
+- eMMC: not directly writable from host — `dd` from the booted board to
+  `/dev/mmcblk1` (or whichever sysfs reports), then reboot and remove SD.
+
+The image self-grows on first boot (`grow-rootfs` OpenRC oneshot fills
+`rootfs` to the disk end + `resize2fs`).
+
+## Default credentials
+
+- root, empty password (development image — change on first login)
+- sshd enabled, `PermitRootLogin yes`, `PermitEmptyPasswords yes`
+
+## Console
+
+`ttyS0 @ 115200 8N1`.  Same UART vendor u-boot uses, no switch needed.
+
+## ISA / GCC
+
+`-march=rv64gc_zba_zbb -mabi=lp64d`.  **Do not** use `-mcpu=sifive-p450`
+— P450 is a superset (Zbs, Zicbom, Zihintpause, Zfhmin) and its codegen
+will SIGILL on real P550 hardware.  GCC mainline has no `sifive-p550`
+entry yet; LLVM does (`SiFiveP500Model`).  Track
+`gcc/config/riscv/riscv-cores.def` for the eventual GCC counterpart.
+
+## Known mainline gaps (v7.2-rc1)
+
+`CONFIG_ARCH_ESWIN=y` landed in defconfig for v7.2-rc1 (commit by
+A. Srinivasan, June 2026).  Remaining gaps:
+
+- **GPU** (Imagination AXM-8-256) — no open Mesa; framebuffer console only
+- **NPU** (19.95 TOPS) — vendor blob only
+- **HDMI display** — vendor only; use serial console
+- **Audio** — disabled in mainline
+- **RTC** — time does not survive reboot (RHEL bug, likely same here)
+
+## Vendor firmware version
+
+Vendor QSPI bootchain matters.  Reported by `u-boot version` at boot:
+
+- `2024.09.00-HFP550` — works
+- `2024.11.00-HFP550` — NIC regression (downgrade if you hit it)
+- `2025.04.00-HFP550` — Fedora minimum
+- `2025.11.00-HFP550` — RHEL 10.2 minimum, current recommendation
+
+Update via SiFive's `EsBurn` (USB) or u-boot `es_burn write 0x90000000 flash`.
+
+## First-batch MAC-ID bug
+
+If your board's MAC reads `8c:1f:64:00:00:00`, the factory failed to
+program it.  Fix with `EsMacIdUpdateTool` from
+`github.com/sifiveinc/hifive-premier-p550-tools`.
+
+## References
+
+- DTS in mainline: `arch/riscv/boot/dts/eswin/eic7700{,-hifive-premier-p550}.dts*`
+- Vendor U-Boot fork (for the QSPI variant): https://github.com/eswincomputing/u-boot tag `u-boot-2024.01-EIC7X`
+- Vendor OpenSBI fork: https://github.com/eswincomputing/opensbi tag `opensbi-1.3-EIC7X`
+- QSPI firmware blobs: https://github.com/sifiveinc/hifive-premier-p550-tools
+- EIC7700X TRM: https://github.com/eswincomputing/EIC7700X-SoC-Technical-Reference-Manual
+- SiFive product page: https://www.sifive.com/boards/hifive-premier-p550

boards/premier-p550/board.conf

@@ -0,0 +1,23 @@
+BOARD_NAME="premier-p550"
+BOARD_ARCH="riscv64"
+BOARD_CFLAGS="-O3 -march=rv64gc_zba_zbb -pipe"
+BOARD_GCC_VERSION="16.1.0"
+CROSS_COMPILE="riscv64-unknown-linux-gnu-"
+KERNEL_ARCH="riscv"
+
+# TODO: back to the stable tree once v7.2 is released.
+KERNEL_REPO="https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git"
+KERNEL_TAG="v7.2-rc1"
+KERNEL_DEFCONFIG="defconfig"
+BOARD_DTB_GLOB="arch/riscv/boot/dts/eswin/eic7700-hifive-premier-p550.dtb"
+
+BOOT_KERNEL_NAME="Image"
+BOOT_CONSOLE="ttyS0,115200"
+BOOT_HOSTNAME="gentoo"
+BOOT_SERIAL_TTY="ttyS0"
+BOOT_SERIAL_BAUD="115200"
+
+# Vendor QSPI already holds OpenSBI + u-boot — skip bootloader step.
+BUILD_STEPS=(deps checkout kernel assemble pack)
+
+BOOT_SERVICES=("sshd:default" "dhcpcd:default")

boards/premier-p550/genimage.cfg

@@ -0,0 +1,55 @@
+config {
+    outputpath = .
+    inputpath = .
+    rootpath = gen
+    tmppath = tmp
+}
+
+image rootfs.ext4 {
+    ext4 {
+        use-mke2fs = "true"
+        label = "rootfs"
+        extraargs = "-i 4k"
+    }
+
+    size = 5G
+    mountpoint = "/root"
+}
+
+# Single FAT bootfs holds the kernel Image, DTB, and
+# extlinux/extlinux.conf, found by vendor u-boot's `bootflow scan`.
+# One FAT partition instead of a separate /boot ext4, matching what
+# SiFive's own Ubuntu and RHEL 10 do on this board.
+image bootfs.vfat {
+    vfat {
+        extraargs = "-F 32"
+        label = "BOOTFS"
+    }
+
+    size = 256M
+    mountpoint = "/boot"
+}
+
+# Single GPT image — dd to microSD / eMMC / NVMe / SATA / USB.
+image gentoo-linux-premier-p550_dev-sdcard.img {
+    hdimage {
+        partition-table-type = gpt
+    }
+
+    partition bootfs {
+        image = "bootfs.vfat"
+        offset = "1M"
+        size = "256M"
+        in-partition-table = "true"
+        partition-type-uuid = "U"
+        bootable = "true"
+    }
+
+    partition rootfs {
+        image = "rootfs.ext4"
+        offset = "257M"
+        size = ""
+        in-partition-table = "true"
+        partition-type-uuid = "root-riscv64"
+    }
+}

boards/premier-p550/override-kernel.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+set -e
+
+# v7.2-rc1 defconfig enables ARCH_ESWIN; the EIC7700 drivers still
+# need turning on.
+
+make -C /build/linux ARCH="${KERNEL_ARCH}" CROSS_COMPILE="${CROSS_COMPILE}" "${KERNEL_DEFCONFIG}"
+
+cat >> /build/linux/.config <<'EOF'
+CONFIG_ARCH_ESWIN=y
+CONFIG_PINCTRL_EIC7700=y
+CONFIG_DWMAC_EIC7700=y
+CONFIG_RESET_EIC7700=y
+CONFIG_COMMON_CLK_ESWIN=y
+CONFIG_COMMON_CLK_EIC7700=y
+CONFIG_PHY_EIC7700_SATA=y
+
+# P550 is RVA20U64 base (rv64imafdc + zba + zbb): no Vector, no
+# T-Head/Andes/MIPS vendor extensions.  Keep the boot-time alternatives
+# patcher from rewriting for extensions this core lacks.
+# CONFIG_RISCV_ISA_V is not set
+# CONFIG_RISCV_ISA_V_DEFAULT_ENABLE is not set
+# CONFIG_RISCV_ISA_XTHEADVECTOR is not set
+# CONFIG_RISCV_ISA_VENDOR_EXT_THEAD is not set
+# CONFIG_RISCV_ISA_VENDOR_EXT_ANDES is not set
+# CONFIG_RISCV_ISA_VENDOR_EXT_MIPS is not set
+# CONFIG_RISCV_ALTERNATIVE_EARLY is not set
+EOF
+
+make -C /build/linux ARCH="${KERNEL_ARCH}" CROSS_COMPILE="${CROSS_COMPILE}" olddefconfig
+make -C /build/linux ARCH="${KERNEL_ARCH}" CROSS_COMPILE="${CROSS_COMPILE}" WERROR=0 -j"$(nproc)"

boards/premier-p550/post-assemble.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+set -e
+
+# Vendor QSPI u-boot's bootflow scan picks up /extlinux/extlinux.conf
+# first.  Keep mem=${ram_size}G from the vendor SDK cmdline: u-boot's
+# extlinux handler expands it (ram_size set by vendor dram_init), and
+# mainline-DTB boots without it die in paging_init (PMP store fault).
+
+dtb_name=$(basename "$(ls /build/gen/boot/*.dtb | head -n1)")
+[ -n "$dtb_name" ] || { echo "Error: no DTB in /build/gen/boot" >&2; exit 1; }
+
+rm -rf /build/gen/boot/extlinux /build/gen/boot/EFI /build/gen/boot/grub
+
+install -d /build/gen/boot/extlinux
+cat > /build/gen/boot/extlinux/extlinux.conf <<EOF
+default gentoo
+timeout 30
+
+label gentoo
+    menu label Gentoo Linux (HiFive Premier P550)
+    kernel /${BOOT_KERNEL_NAME}
+    fdt /${dtb_name}
+    append root=PARTLABEL=rootfs rootfstype=ext4 rootwait earlycon=sbi console=${BOOT_CONSOLE}n8 mem=\${ram_size}G
+EOF