On 5/3/23 08:41, [email protected] wrote:
Hi,
Inside
-----Original Message-----
From: Philippe Mathieu-Daudé <[email protected]>
Sent: Thursday, December 22, 2022 5:03 PM
To: Havard Skinnemoen <[email protected]>; [email protected]
Cc: [email protected]; [email protected]; IS20 Avi Fishman
<[email protected]>; CS20 KFTing <[email protected]>; Alexander
Bulekov <[email protected]>; Shengtan Mao <[email protected]>; Hao Wu
<[email protected]>; Chris Rauer <[email protected]>; CS20 KFTing
<[email protected]>
Subject: Re: [PATCH v9 08/14] hw/nvram: NPCM7xx OTP device model
Hi,
(old patch)
On 11/9/20 07:20, Havard Skinnemoen wrote:
This supports reading and writing OTP fuses and keys. Only fuse reading
has been tested. Protection is not implemented.
Reviewed-by: Avi Fishman <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Alexander Bulekov <[email protected]>
Signed-off-by: Havard Skinnemoen <[email protected]>
---
include/hw/arm/npcm7xx.h | 3 +
include/hw/nvram/npcm7xx_otp.h | 79 ++++++
hw/arm/npcm7xx.c | 29 +++
hw/nvram/npcm7xx_otp.c | 440 +++++++++++++++++++++++++++++++++
hw/nvram/meson.build | 1 +
5 files changed, 552 insertions(+)
create mode 100644 include/hw/nvram/npcm7xx_otp.h
create mode 100644 hw/nvram/npcm7xx_otp.c
+/**
+ * npcm7xx_otp_array_write - ECC encode and write data to OTP array.
+ * @s: OTP module.
+ * @data: Data to be encoded and written.
+ * @offset: Offset of first byte to be written in the OTP array.
+ * @len: Number of bytes before ECC encoding.
+ *
+ * Each nibble of data is encoded into a byte, so the number of bytes written
+ * to the array will be @len * 2.
+ */
+extern void npcm7xx_otp_array_write(NPCM7xxOTPState *s, const void
*data,
+ unsigned int offset, unsigned int len);
+static void npcm7xx_init_fuses(NPCM7xxState *s)
+{
+ NPCM7xxClass *nc = NPCM7XX_GET_CLASS(s);
+ uint32_t value;
+
+ /*
+ * The initial mask of disabled modules indicates the chip derivative (e.g.
+ * NPCM750 or NPCM730).
+ */
+ value = tswap32(nc->disabled_modules);
In which endianness do you want this 32-bit fuse value to be written?
It should be little endian, I am not sure why there is a swap here.
Unless the nc->disabled_modules for some reason is coming swapped so we swap it
back.
I suppose you used a little-endian host, so we want it big-endian in
the OTP? In that case it would be better to use cpu_to_be32(), to
be able to use the OTP on a big-endian host such s390x.
So according to what I said then use cpu_to_le32()
Thank you Avi!
