Timur,
That patch itself is OK. But the comment is incorrect. We keep adding more mac
addresses to this data structure. The CRC was at the end. The offset 0xCC was
correct.
York
On Jul 12, 2012, at 2:46 PM, Timur Tabi wrote:
> The NXID v1 EEPROM format has the CRC at offset 0xFC, but for some reason it
> was placed at address 0xCC instead. To retain compatibility with existing
> boards, we check the CRC in the old location if necessary.
>
> Signed-off-by: Timur Tabi <ti...@freescale.com>
> ---
> board/freescale/common/sys_eeprom.c | 28 ++++++++++++++++++++++++++--
> 1 files changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/board/freescale/common/sys_eeprom.c
> b/board/freescale/common/sys_eeprom.c
> index d2ed036..2541dd2 100644
> --- a/board/freescale/common/sys_eeprom.c
> +++ b/board/freescale/common/sys_eeprom.c
> @@ -34,8 +34,16 @@
> #endif
>
> #ifdef CONFIG_SYS_I2C_EEPROM_NXID
> -#define MAX_NUM_PORTS 23
> +#define MAX_NUM_PORTS 31
> #define NXID_VERSION 1
> +
> +/*
> + * Older versions of this code incorrectly placed the CRC at offset 0xCC,
> + * when it should have been at 0xFC. To maintain compatibility with boards
> + * that have the CRC at 0xCC, we check for the CRC at 0xCC if it's not in
> + * 0xFC.
> + */
> +#define BROKEN_CRC_OFFSET 0xCC
> #endif
>
> /**
> @@ -71,7 +79,7 @@ static struct __attribute__ ((__packed__)) eeprom {
> u8 mac_count; /* 0x40 Number of MAC addresses */
> u8 mac_flag; /* 0x41 MAC table flags */
> u8 mac[MAX_NUM_PORTS][6]; /* 0x42 - x MAC addresses */
> - u32 crc; /* x+1 CRC32 checksum */
> + u32 crc; /* 0xFC CRC32 checksum */
> #endif
> } e;
>
> @@ -457,6 +465,22 @@ int mac_read_from_eeprom(void)
>
> crc = crc32(0, (void *)&e, crc_offset);
> crcp = (void *)&e + crc_offset;
> +#ifdef BROKEN_CRC_OFFSET
> + /*
> + * If the CRC is wrong, then check the old location. If it contains a
> + * valid CRC, then assume that this is an older EEPROM. We update the
> + * real CRC so that the EEPROM looks valid.
> + */
> + if ((e.version == NXID_VERSION) && (crc != be32_to_cpup(crcp))) {
> + u32 crc2 = crc32(0, (void *)&e, BROKEN_CRC_OFFSET);
> + void *crcp2 = (void *)&e + BROKEN_CRC_OFFSET;
> +
> + if (crc2 == be32_to_cpup(crcp2)) {
> + debug("Broken NXID v1 CRC found and corrected\n");
> + update_crc();
> + }
> + }
> +#endif
> if (crc != be32_to_cpu(*crcp)) {
> printf("CRC mismatch (%08x != %08x)\n", crc,
> be32_to_cpu(e.crc));
> return -1;
> --
> 1.7.3.4
>
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