[Qemu-devel] CFI02 flashes

[Qemu-devel] CFI02 flashes

[Edgar E. Iglesias]

Hello,

I ran into problems when mounting jffs2 images on CFI02 flashes on a linux
guest. Looks like we got some fields wrong in our CFI table.

We are reporting a too large device size, MTD doesn't like that.
We are reporting timing info for buffer writes, this makes MTD beleive we
support buffer writes leading failures when programming.
Also linux MTD seems to require an extended CFI table to use the device.

This patch seems to work (only tested with ETRAX/CRIS).
Comments?

Best regards
--
Edgar E. Iglesias
Axis Communications AB

commit 7f62e4f49c65f64ef8624474c5d22d9785d9b18c
Author: Edgar E. Iglesias <edgar.iglesias@axis.com>
Date:   Thu May 8 01:48:55 2008 +0200

    CFI-0002 linux MTD compatibility.
    * Add an extended table area.
    * Clear buffer write timeouts to indicate that we dont support it.
    * Correct device size.

diff --git a/hw/pflash_cfi02.c b/hw/pflash_cfi02.c
index cb9b250..1daaac3 100644
--- a/hw/pflash_cfi02.c
+++ b/hw/pflash_cfi02.c
@@ -608,8 +608,8 @@ pflash_t *pflash_cfi02_register(target_phys_addr_t base, ram_addr_t off,
     /* Command set (AMD/Fujitsu) */
     pfl->cfi_table[0x13] = 0x02;
     pfl->cfi_table[0x14] = 0x00;
-    /* Primary extended table address (none) */
-    pfl->cfi_table[0x15] = 0x00;
+    /* Primary extended table address */
+    pfl->cfi_table[0x15] = 0x31;
     pfl->cfi_table[0x16] = 0x00;
     /* Alternate command set (none) */
     pfl->cfi_table[0x17] = 0x00;
@@ -627,22 +627,22 @@ pflash_t *pflash_cfi02_register(target_phys_addr_t base, ram_addr_t off,
     pfl->cfi_table[0x1E] = 0x00;
     /* Reserved */
     pfl->cfi_table[0x1F] = 0x07;
-    /* Timeout for min size buffer write (16 ÄĐs) */
-    pfl->cfi_table[0x20] = 0x04;
+    /* Timeout for min size buffer write (NA) */
+    pfl->cfi_table[0x20] = 0x00;
     /* Typical timeout for block erase (512 ms) */
     pfl->cfi_table[0x21] = 0x09;
     /* Typical timeout for full chip erase (4096 ms) */
     pfl->cfi_table[0x22] = 0x0C;
     /* Reserved */
     pfl->cfi_table[0x23] = 0x01;
-    /* Max timeout for buffer write */
-    pfl->cfi_table[0x24] = 0x04;
+    /* Max timeout for buffer write (NA) */
+    pfl->cfi_table[0x24] = 0x00;
     /* Max timeout for block erase */
     pfl->cfi_table[0x25] = 0x0A;
     /* Max timeout for chip erase */
     pfl->cfi_table[0x26] = 0x0D;
     /* Device size */
-    pfl->cfi_table[0x27] = ctz32(chip_len) + 1;
+    pfl->cfi_table[0x27] = ctz32(chip_len);
     /* Flash device interface (8 & 16 bits) */
     pfl->cfi_table[0x28] = 0x02;
     pfl->cfi_table[0x29] = 0x00;
@@ -659,5 +659,23 @@ pflash_t *pflash_cfi02_register(target_phys_addr_t base, ram_addr_t off,
     pfl->cfi_table[0x2F] = sector_len >> 8;
     pfl->cfi_table[0x30] = sector_len >> 16;
 
+    /* Extended */
+    pfl->cfi_table[0x31] = 'P';
+    pfl->cfi_table[0x32] = 'R';
+    pfl->cfi_table[0x33] = 'I';
+
+    pfl->cfi_table[0x34] = '1';
+    pfl->cfi_table[0x35] = '0';
+
+    pfl->cfi_table[0x36] = 0x00;
+    pfl->cfi_table[0x37] = 0x00;
+    pfl->cfi_table[0x38] = 0x00;
+    pfl->cfi_table[0x39] = 0x00;
+
+    pfl->cfi_table[0x3a] = 0x00;
+
+    pfl->cfi_table[0x3b] = 0x00;
+    pfl->cfi_table[0x3c] = 0x00;
+
     return pfl;
 }

Re: [Qemu-devel] CFI02 flashes

[Jan Kiszka]

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Edgar E. Iglesias wrote:
> Hello,
> 
> I ran into problems when mounting jffs2 images on CFI02 flashes on a linux
> guest. Looks like we got some fields wrong in our CFI table.
> 
> We are reporting a too large device size, MTD doesn't like that.
> We are reporting timing info for buffer writes, this makes MTD beleive we
> support buffer writes leading failures when programming.
> Also linux MTD seems to require an extended CFI table to use the device.
> 
> This patch seems to work (only tested with ETRAX/CRIS).
> Comments?

No regressions found for the MusicPal (which uses cfi02 as well). But...

> 
> Best regards
> --
> Edgar E. Iglesias
> Axis Communications AB
> 
> commit 7f62e4f49c65f64ef8624474c5d22d9785d9b18c
> Author: Edgar E. Iglesias <edgar.iglesias@axis.com>
> Date:   Thu May 8 01:48:55 2008 +0200
> 
>     CFI-0002 linux MTD compatibility.
>     * Add an extended table area.
>     * Clear buffer write timeouts to indicate that we dont support it.
>     * Correct device size.
> 
> diff --git a/hw/pflash_cfi02.c b/hw/pflash_cfi02.c
> index cb9b250..1daaac3 100644
> --- a/hw/pflash_cfi02.c
> +++ b/hw/pflash_cfi02.c
> @@ -608,8 +608,8 @@ pflash_t *pflash_cfi02_register(target_phys_addr_t base, ram_addr_t off,
>      /* Command set (AMD/Fujitsu) */
>      pfl->cfi_table[0x13] = 0x02;
>      pfl->cfi_table[0x14] = 0x00;
> -    /* Primary extended table address (none) */
> -    pfl->cfi_table[0x15] = 0x00;
> +    /* Primary extended table address */
> +    pfl->cfi_table[0x15] = 0x31;
>      pfl->cfi_table[0x16] = 0x00;
>      /* Alternate command set (none) */
>      pfl->cfi_table[0x17] = 0x00;
> @@ -627,22 +627,22 @@ pflash_t *pflash_cfi02_register(target_phys_addr_t base, ram_addr_t off,
>      pfl->cfi_table[0x1E] = 0x00;
>      /* Reserved */
>      pfl->cfi_table[0x1F] = 0x07;
> -    /* Timeout for min size buffer write (16 ÄĐs) */

... I had to apply you patch manually due to this encoding issue.

Jan


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