On 22 December 2016 at 14:02, David Engraf <david.eng...@sysgo.com> wrote: > The current implementation uses width = 4 and device-width = 2 for the flash > configuration. When using u-boot or Linux, the flash is detected as 32 x 16 > bit, thus the sector size is doubled to 512 KB. When u-boot sends a sector > erase, only the first 256 KB are erased because the QEMU flash > implementation uses the configured sector size of 256 KB and ignores the > width and device-width ratio. > > This patch will change device-width to 4, thus the width and device-width > are equal and u-boot detects the flash as 32 x 32 bit with the correct > sector size of 256 KB.
Thanks for this patch. However I'm not sure it is correct, because I think the real hardware does have 2x16 devices here. On real vexpress TC2 if you boot Linux it detects the flash as: "8000000.flash: Found 2 x16 devices at 0x0 in 32-bit bank. Manufacturer ID 0x000089 Chip ID 0x008919" So while we presumably have a QEMU bug if this isn't behaving like the hardware, I don't think that changing the device-width to 4 is the right fix for it. Maybe: * our erase implementation is broken? * one of the other parameters we use to create the flash is wrong? * the calculation of the erase block information that we put in the flash cfi_table[] is wrong? (Does u-boot hard-code the erase block sizes, or does it read them from the CFI data? QEMU's flash doesn't have the hardware's two-eraseblock-regions setup where part of the disk is 256K erase-blocks and part is 64K blocks, but if u-boot doesn't hardcode that it should be able to read the data from QEMU's flash implementation.) Also, for patches to QEMU we need you to provide a Signed-off-by: line to say that you're happy to contribute the patch to QEMU. More detail about what this means here: http://wiki.qemu.org/Contribute/SubmitAPatch#Patch_emails_must_include_a_Signed-off-by:_line (the other details of patch formatting are mostly nice-to-haves, but the s-o-by line is a hard requirement.) thanks -- PMM
