[PATCH v3 0/4] Initial ESWIN/EIC7700 support
Bo Gan
ganboing at gmail.com
Thu Nov 20 01:34:36 PST 2025
EIC7700 is the SoC used in HiFive P550 and Milk-V Megrez. This SoC is
currently one of the only off-the-shelf board/chips that support H
extension, although it's v0.6.1. It also supports pre-ratified N-trace.
Add support for it so people can benefit from latest OpenSBI features.
The device-tree of HiFive P550 has been upstreamed to Linux:
https://lore.kernel.org/all/20250825132427.1618089-1-pinkesh.vaghela@einfochips.com/
However U-boot is not, and there are bugs in vendor U-boot device-tree,
and also inconsistencies between the two. Thus, this patch is coded with
the upstreamed device-tree as the reference, but tested with the patched
vendor U-boot device tree as `FW_FDT_PATH`. The patched vendor U-boot is
hosted here: https://github.com/ganboing/u-boot-eic7x/tree/eic7x-dt-fix
Refer to the last PATCH for the instructions on building the firmware
blob and launch it through UART boot.
The major complication of this chip is that it requires certain memory
regions to be blocked with PMP entries to prevent speculative execution
or HW prefetcher from touching the data-cacheable regions within to
avoid bus errors. Due to the fact that this SoC handles cache incoherent
DMA by mapping memory twice, one as cached, and the other as uncached,
we also need an extra PMP to protect the OpenSBI in the uncached portion
in address space. The PMP handling is tricky, so I documented it very
extensively for people to reason about it. I managed to get it done with
only NAPOT PMP entries and still got 1 free PMP for root harts for die 0
(No free PMP for die 1 root harts). This even permits a udomain/tdomain
like partitioning, so we can even try out TEEs. Sample boot log:
OpenSBI v1.7-73-g5c235e5d
____ _____ ____ _____
/ __ \ / ____| _ \_ _|
| | | |_ __ ___ _ __ | (___ | |_) || |
| | | | '_ \ / _ \ '_ \ \___ \| _ < | |
| |__| | |_) | __/ | | |____) | |_) || |_
\____/| .__/ \___|_| |_|_____/|____/_____|
| |
|_|
Platform Name : SiFive HiFive Premier P550
Platform Features : medeleg
Platform HART Count : 4
Platform IPI Device : aclint-mswi
Platform Timer Device : aclint-mtimer @ 1000000Hz
Platform Console Device : uart8250
Platform HSM Device : ---
Platform PMU Device : ---
Platform Reboot Device : eic770x_reset
Platform Shutdown Device : ---
Platform Suspend Device : ---
Platform CPPC Device : ---
Firmware Base : 0x80000000
Firmware Size : 613 KB
Firmware RW Offset : 0x80000
Firmware RW Size : 101 KB
Firmware Heap Offset : 0x8d000
Firmware Heap Size : 49 KB (total), 1 KB (reserved), 14 KB (used), 33 KB (free)
Firmware Scratch Size : 4096 B (total), 424 B (used), 3672 B (free)
Runtime SBI Version : 3.0
Standard SBI Extensions : time,rfnc,ipi,base,hsm,srst,pmu,dbcn,fwft,legacy,dbtr,sse
Experimental SBI Extensions : none
Domain0 Name : root
Domain0 Boot HART : 0
Domain0 HARTs : 0*,1*,2*,3*
Domain0 Region00 : 0x0000000080000000-0x00000000800fffff M: (F,R,W,X) S/U: ()
Domain0 Region01 : 0x000000c000000000-0x000000c0000fffff M: (F,R,W,X) S/U: ()
Domain0 Region02 : 0x0000000002000000-0x000000000200ffff M: (I,R,W) S/U: ()
Domain0 Region03 : 0x0000000000000000-0x000000007fffffff M: (I,R,W) S/U: (R,W)
Domain0 Region04 : 0x0000000000000000-0x0000000fffffffff M: (R,W) S/U: (R,W,X)
Domain0 Region05 : 0x0000000000000000-0x0000007fffffffff M: (I) S/U: ()
Domain0 Region06 : 0x0000000000000000-0xffffffffffffffff M: () S/U: (R,W,X)
Domain0 Next Address : 0x0000000080200000
Domain0 Next Arg1 : 0x00000000f8000000
Domain0 Next Mode : S-mode
Domain0 SysReset : yes
Domain0 SysSuspend : yes
Domain1 Name : trusted-domain
Domain1 Boot HART : -1
Domain1 HARTs :
Domain1 Region00 : 0x0000000080000000-0x00000000800fffff M: (F,R,W,X) S/U: ()
Domain1 Region01 : 0x000000c000000000-0x000000c0000fffff M: (F,R,W,X) S/U: ()
Domain1 Region02 : 0x0000000050910000-0x0000000050910fff M: (I,R,W) S/U: (R,W)
Domain1 Region03 : 0x0000000002000000-0x000000000200ffff M: (I,R,W) S/U: ()
Domain1 Region04 : 0x000000047ff00000-0x000000047fffffff M: () S/U: (R,W,X)
Domain1 Region05 : 0x0000000000000000-0x000000007fffffff M: (I,R,W) S/U: ()
Domain1 Region06 : 0x0000000000000000-0x0000007fffffffff M: (I) S/U: ()
Domain1 Next Address : 0x000000047ff00000
Domain1 Next Arg1 : 0x0000000000000000
Domain1 Next Mode : S-mode
Domain1 SysReset : no
Domain1 SysSuspend : no
Domain2 Name : untrusted-domain
Domain2 Boot HART : -1
Domain2 HARTs :
Domain2 Region00 : 0x0000000080000000-0x00000000800fffff M: (F,R,W,X) S/U: ()
Domain2 Region01 : 0x000000c000000000-0x000000c0000fffff M: (F,R,W,X) S/U: ()
Domain2 Region02 : 0x0000000002000000-0x000000000200ffff M: (I,R,W) S/U: ()
Domain2 Region03 : 0x000000047ff00000-0x000000047fffffff M: () S/U: ()
Domain2 Region04 : 0x0000000000000000-0x0000000fffffffff M: (R,W) S/U: (R,W,X)
Domain2 Region05 : 0x0000000000000000-0x0000007fffffffff M: (I) S/U: ()
Domain2 Region06 : 0x0000000000000000-0xffffffffffffffff M: () S/U: (R,W,X)
Domain2 Next Address : 0x0000000080000000
Domain2 Next Arg1 : 0x00000000f8000000
Domain2 Next Mode : S-mode
Domain2 SysReset : no
Domain2 SysSuspend : no
Boot HART ID : 0
Boot HART Domain : root
Boot HART Priv Version : v1.11
Boot HART Base ISA : rv64imafdchx
Boot HART ISA Extensions : sscofpmf,zihpm,sdtrig
Boot HART PMP Count : 8
Boot HART PMP Granularity : 12 bits
Boot HART PMP Address Bits : 39
Boot HART MHPM Info : 4 (0x00000078)
Boot HART Debug Triggers : 4 triggers
Boot HART MIDELEG : 0x0000000000002666
Boot HART MEDELEG : 0x0000000000f0b509
Signed-off-by: Bo Gan <ganboing at gmail.com>
---
Changes in v3:
- Figure out the cause behind bus error, and document it properly
- Drop the consolidation logic and let the lib/memregion logic to
optimize out unnecessary regions -- simplifies many things.
- Better and more comprehensive comments in source code.
- Support tdomain/udomain like use cases on die 0.
Changes in v2:
- Major enhancement of PMP consolidation logic. Also fixed a Linux
Panic bug due to the mismatch between PMP settings and reserved
memory regions passed to Linux via FDT.
- Also protects the OpenSBI firmware in uncached memory portion of
address space.
- More detailed documentation on EIC770X/P550
---
Bo Gan (4):
lib: sbi: allow platform to override PMP (un)configuration
lib: sbi: give platform choice of using single memregion to cover
OpenSBI
include: sbi_domain: make is_region_subset public
platform: generic: eswin: add EIC7700
include/sbi/sbi_domain.h | 29 ++
include/sbi/sbi_hart.h | 3 +
include/sbi/sbi_platform.h | 74 +++++
lib/sbi/sbi_domain.c | 80 +++--
lib/sbi/sbi_domain_context.c | 11 +-
lib/sbi/sbi_hart.c | 45 ++-
platform/generic/Kconfig | 5 +
platform/generic/configs/defconfig | 1 +
platform/generic/eswin/Kconfig | 29 ++
platform/generic/eswin/eic770x.c | 385 +++++++++++++++++++++++
platform/generic/eswin/objects.mk | 11 +
platform/generic/include/eswin/eic770x.h | 73 +++++
12 files changed, 687 insertions(+), 59 deletions(-)
create mode 100644 platform/generic/eswin/Kconfig
create mode 100644 platform/generic/eswin/eic770x.c
create mode 100644 platform/generic/eswin/objects.mk
create mode 100644 platform/generic/include/eswin/eic770x.h
--
2.34.1
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