On 10/10/22 11:58, Michael Walle wrote:
Am 2022-10-10 08:23, schrieb Cédric Le Goater:
On 10/7/22 16:44, Francisco Iglesias wrote:
--- a/hw/block/m25p80.c
+++ b/hw/block/m25p80.c
@@ -234,6 +234,8 @@ static const FlashPartInfo known_devices[] = {
{ INFO("mx25l12855e", 0xc22618, 0, 64 << 10, 256, 0) },
{ INFO6("mx25l25635e", 0xc22019, 0xc22019, 64 << 10, 512, 0),
.sfdp_read = m25p80_sfdp_mx25l25635e },
+ { INFO6("mx25l25635f", 0xc22019, 0xc22019, 64 << 10, 512, 0),
I think I'm not seeing the extended id part in the datasheet I've found so
might be that you can switch to just INFO and _ext_id 0 above
This was added by commit 6bbe036f32dc ("m25p80: Return the JEDEC ID twice for
mx25l25635e") to fix a real breakage on HW.
From my experience, the ID has a particular length, at least three bytes
and if you read past that length for some (all?) devices the id bytes just
get repeated. I.e. the counter in the device will just wrap to offset 0
again.
At the time, I did some specific tests on these mx25l25635e chips and
this how they behaved. I can not check anymore as I don't have access
to these systems.
If you want to emulate the hardware correctly, you would have to
take that into consideration.
But this is not the case for all chips, most return 0 and don't
wrap around. I just did on w25q512jvq and w25q256 chips with a 6.0.
But I don't think it's worth it, OTOH there seems to be some broken
software which rely on that (undefined?) behavior.
I can't really tell :/ The driver (kernel based Linux 2.6.28) reads
4 bytes and expect the last to be the Manufacturer id: 0xC2. That's
valid for this chip.
Setting an extended ID in the flash info is an alternative :
{ INFO("mx25l25635e", 0xc22019, 0xc200, ...
which does not seem to break other machines using mx25l25635e, with
recent kernels at least.
To reproduce, grab :
http://smbserver.frankfurt.de.velia.net/ipmi/SMT_X11_158.bin
Run :
qemu-system-arm -M supermicrox11-bmc -nic user -drive
file=./SMT_X11_158.bin,format=raw,if=mtd -nographic -serial mon:stdio
...
BMC flash ID:0xc21920c2
platform_flash: MX25L25635E (32768 Kbytes)
Creating 7 MTD partitions on "spi0.0":
...
C.
