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* [RFC PATCH v2 0/2] Add write-once and file-backed features to OTP
@ 2020-07-31  2:47 Green Wan
  2020-07-31  2:47 ` [RFC PATCH v2 1/2] hw/riscv: sifive_u: Add file-backed OTP Green Wan
  2020-07-31  2:47 ` [RFC PATCH v2 2/2] hw/riscv: sifive_u: Add write-once protection Green Wan
  0 siblings, 2 replies; 7+ messages in thread
From: Green Wan @ 2020-07-31  2:47 UTC (permalink / raw)
  Cc: qemu-riscv, Sagar Karandikar, Bastian Koppelmann, qemu-devel,
	Green Wan, Alistair Francis, Palmer Dabbelt, bmeng.cn

First patch is to add file-backed implementation to allow users to assign
an OTP image file to machine. Users can assign the property, "otp-file",
to machine to enable it. File-backed feature is set to "NULL" string in
default. Any filename other than "NULL" is used as OTP image file.

For example, '-M sifive_u,otp-file="otp.img"'

To keep data up-to-date due to an unexpected crash or CTRL+a-x exit, every
read/write command to OTP memory involves file open, mmap and close
operation to the image file.

Second patch is to add 'write-once' feature to block second write to the
OTP memory. Only keep the 'written' state for non-control register range
from 0x38 to 16KB.

Tested on sifive_u for both qemu and u-boot.

Green Wan (2):
  hw/riscv: sifive_u: Add file-backed OTP.
  hw/riscv: sifive_u: Add write-once protection.

 hw/riscv/sifive_u.c             |  26 ++++++++
 hw/riscv/sifive_u_otp.c         | 103 ++++++++++++++++++++++++++++++++
 include/hw/riscv/sifive_u.h     |   2 +
 include/hw/riscv/sifive_u_otp.h |   2 +
 4 files changed, 133 insertions(+)

-- 
2.17.1



^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2020-08-18 17:14 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-31  2:47 [RFC PATCH v2 0/2] Add write-once and file-backed features to OTP Green Wan
2020-07-31  2:47 ` [RFC PATCH v2 1/2] hw/riscv: sifive_u: Add file-backed OTP Green Wan
2020-08-10 22:13   ` Alistair Francis
2020-08-13  4:12     ` Green Wan
2020-08-13 21:24       ` Alistair Francis
2020-08-18 17:12         ` Green Wan
2020-07-31  2:47 ` [RFC PATCH v2 2/2] hw/riscv: sifive_u: Add write-once protection Green Wan

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