From: Larry Finger <Larry.Finger@lwfinger.net>
To: Michael Straube <straube.linux@gmail.com>
Cc: Phillip Potter <phil@philpotter.co.uk>,
Greg KH <gregkh@linuxfoundation.org>,
"open list:STAGING SUBSYSTEM" <linux-staging@lists.linux.dev>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: staging: r8188eu: struct rt_firmware_header issues
Date: Wed, 13 Apr 2022 16:12:07 -0500 [thread overview]
Message-ID: <bffc888b-5f22-6b3d-9762-2a90a33fa530@lwfinger.net> (raw)
In-Reply-To: <86a66ea4-45e3-cfa2-9130-f698ae212bfd@gmail.com>
On 4/13/22 14:42, Michael Straube wrote:
> On 4/13/22 18:27, Michael Straube wrote:
>> Hi all,
>>
>> I think the rt_firmware_hdr structure in rtw_fw.c has some issues.
>>
>>
>> struct rt_firmware_hdr {
>> /* 8-byte alinment required */
>> /* LONG WORD 0 ---- */
>> __le16 Signature; /* 92C0: test chip; 92C,
>> * 88C0: test chip; 88C1: MP A-cut;
>> * 92C1: MP A-cut */
>> u8 Category; /* AP/NIC and USB/PCI */
>> u8 Function; /* Reserved for different FW function
>> * indcation, for further use when
>> * driver needs to download different
>> * FW for different conditions */
>> __le16 Version; /* FW Version */
>> u8 Subversion; /* FW Subversion, default 0x00 */
>> u16 Rsvd1;
>>
>> /* LONG WORD 1 ---- */
>> u8 Month; /* Release time Month field */
>> u8 Date; /* Release time Date field */
>> u8 Hour; /* Release time Hour field */
>> u8 Minute; /* Release time Minute field */
>> __le16 RamCodeSize; /* The size of RAM code */
>> u8 Foundry;
>> u8 Rsvd2;
>>
>> /* LONG WORD 2 ---- */
>> __le32 SvnIdx; /* The SVN entry index */
>> u32 Rsvd3;
>>
>> /* LONG WORD 3 ---- */
>> u32 Rsvd4;
>> u32 Rsvd5;
>> };
>>
>>
>> Then we have in rtl8188e_firmware_download():
>>
>>
>> fwhdr = (struct rt_firmware_hdr *)dvobj->firmware.data;
>>
>> <snip>
>>
>> if (IS_FW_HEADER_EXIST(fwhdr)) {
>> /* Shift 32 bytes for FW header */
>> fw_data = fw_data + 32;
>> fw_size = fw_size - 32;
>> }
>>
>> We add/sub 32 bytes but the size of struct rt_firmware_hdr is actually
>> 33 bytes. I noticed this when I wanted to replace:
>>
>> fw_data = fw_data + 32;
>> fw_size = fw_size - 32;
>>
>> with:
>> fw_data = fw_data + sizeof(struct rt_firmware_hdr);
>> fw_size = fw_size - sizeof(struct rt_firmware_hdr);;
>>
>> To me it looks add/sub 32 is correct here but the struct is
>> wrong. I don't know if the firmware for this driver is so much different
>> from firmware for the drivers in drivers/net/wireless/realtek/rtlwifi.
>> They use a struct of size 32.
>>
>> Also, souldn't the u16 and u32 variables in the struct be __le16 and
>> __le32 ?
>>
>> I wonder if we can just use the rtlwifi_firmware_header structure from
>> drivers/net/wireless/realtek/rtlwifi/wifi.h ?
>>
>> Comments from people with better knowledge appreciated. :)
>>
>> regards,
>> Michael
>>
>>
>
> Ok, I figured it out by looking at the hexdumps of firmware files. The
> field Rsvd1 should be u8 instead of u16. I'll prepare a patch for this.
I agree. I had prepared an analysis, but did not get it mailed before I got this
one.
Larry
next prev parent reply other threads:[~2022-04-13 21:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-13 16:27 staging: r8188eu: struct rt_firmware_header issues Michael Straube
2022-04-13 19:42 ` Michael Straube
2022-04-13 21:12 ` Larry Finger [this message]
2022-04-14 8:41 ` David Laight
2022-04-14 10:08 ` Michael Straube
2022-04-14 10:14 ` David Laight
2022-04-14 15:46 ` Larry Finger
2022-04-13 20:58 ` Pavel Skripkin
2022-04-13 21:26 ` Michael Straube
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