Re: [U-Boot] Integity validation (checksum) of a squashfs root file system

Hi M,

this is very similar to my actual solution with iminfo (see below). In fact, the main question is: Is it generic enough to be integrated in u-boot development tree? Is it better to modify sha1sum instead? Or finally, a more generic approach is to offer a command to set an environment variable from memory content like: md [.b, .w, .l] address [# of objects] [environment variable name] So, when a variable name is specified, "md" sets env. variable with the memory content.

Regards,

Pascal

--- a/common/cmd_bootm.c +++ b/common/cmd_bootm.c @@ -1097,6 +1097,7 @@ static int image_info(ulong addr) { void *hdr = (void *)addr; + char str[80];

printf("\n## Checking Image at %08lx ...\n", addr);

@@ -1120,6 +1121,16 @@ puts(" Bad Data CRC\n"); return 1; } + + sprintf(str, "%lx", image_get_data_size(hdr)); /* write data size into string */ + setenv("image_data_size", str); + sprintf(str, "%lx", image_get_dcrc(hdr)); /* write data crc into string */ + setenv("image_data_crc", str); + sprintf(str, "%lx", image_get_data(hdr)); /* write data start address into string */ + setenv("image_data_addr"); + sprintf(str, "%lx", image_get_time(hdr)); /* write image timestamp into string */ + setenv("image_timestamp", str); + puts("OK\n"); return 0; #if defined(CONFIG_FIT)

-----Original Message----- From: Marek Vasut Sent: Monday, February 06, 2012 1:41 PM To: Pascal Levesque Cc: u-boot@lists.denx.de Subject: Re: [U-Boot] Integity validation (checksum) of a squashfs root file system

Hi M,

sha1sum does provide a console output but nothing that could be used for an automated check like crc32 -v...

Make it export an env. variable?

M

Pascal

-----Original Message----- From: Marek Vasut Sent: Monday, February 06, 2012 11:34 AM To: u-boot@lists.denx.de Cc: Pascal Levesque Subject: Re: [U-Boot] Integity validation (checksum) of a squashfs root file system

...

Hi,

I would like to validate the integrity (checksum) of a squashfs root file system before starting Linux.

Current strategy I am using is:

• Wrap squashfs rootfs inside a u-boot image
• TFTP download on the target
• Download validation using iminfo
• Save squashfs rootfs in flash without the image header (Linux failed

to load squashfs rootfs if u-boot image is present)

Problems:

• I need to hardcode squashfs rootfs offset in u-boot image in order to

be able to flash it - U-Boot image header information (size, crc, ...) is lost after a reboot. It is not possible to check the integrity of the flash content.

I would like to save some fields of u-boot image header (size, crc, ...) in u-boot environment variables. And then do an integrity check at boot time.

I have not find a way to extract those fields and save them without changing u-boot code. I have added some code to “iminfo” command to set environment variables for CRC, size, payload offset, timestamp.

Is it an acceptable way of doing it? Is there a better way of doing it?

Thanks in advance,

Pascal

Use sha1sum integrated into uboot and stick it at the end?

M