Add blank check to algorithm #3345
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| .map_err(FlashError::Core)?; | ||
| if !data | ||
| .iter() | ||
| .all(|v| *v == self.flash_algorithm.flash_properties.erased_byte_value) |
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Just want to note that there are a few chips that have 2-byte erase values. You don't need to do anything about those here, I think we lose that information somewhere in target-gen, but I'll leave this comment here in case someone looks at this PR.
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The fallback algorithm is the one that used to be from target-gen/src/commands/test.rs so there isn't a regression in functionality here.
Such devices could actually benefit from a flash algorithm that runs on the device, or we can add something like erased_u16_value or erased_short_value to the flash algorithm definition so we can support those devices in the future.
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| @@ -66,6 +66,9 @@ pub struct RawFlashAlgorithm { | |||
| /// Address of the (non-standard) `ReadFlash()` entry point. Optional. | |||
| #[serde(serialize_with = "hex_option")] | |||
| pub pc_read: Option<u64>, | |||
| /// Address of the (non-standard) `BlankCheck()` entry point. Optional. | |||
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BlankCheck is a standard CMSIS-PACK function. https://open-cmsis-pack.github.io/Open-CMSIS-Pack-Spec/main/html/algorithmFunc.html
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I had no idea. I'll update the comment.
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It's not just the comment. I'd prefer not breaking handwritten flash algos that decide to support "OurBlankCheck" when we decide to support the upstream function, so we should make sure we don't expect this custom addition to be called the same in the flash algo either.
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I can rename the function. Currently, flash-algorithm generates a function called BlankCheck, but I can submit a patch to update that as well.
What name would you like?
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I'm fine with whatever, even BlankCheck2 🫠 so long as it's different from the standard name.
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We could use that, but it's a big enough change that perhaps @bugadani didn't want that. I'm fine with either approach.
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I just thought we don't know the empty flash pattern upfront and can't use the standard method 🤔 I'd also prefer that, to be fair. The change itself should be largely the same - we just need to call the function with an extra argument.
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It doesn't say the pattern argument has to be used:
The function BlankCheck can be used to check whether the specified block is empty, or whether the content is equal to a specific pattern defined in the argument pat.
I imagine that statement means that a function is free to ignore the third argument if it makes sense.
Let me rework the patch back to the original function name, and make the arguments line up with the CMSIS-DAP implementation.
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Algos carry the default erased value: https://open-cmsis-pack.github.io/Open-CMSIS-Pack-Spec/main/html/flashAlgorithm.html#AddFPA and we have it present in the target YAMLs :)
(admittedly I have no idea how correct those are)
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Alright, blank_check() now has three arguments that follow the CMSIS-DAP implementation of BlankCheck
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Some parts have special requirements for determining whether it is blank. Add functions to perform this operation. Signed-off-by: Sean Cross <sean@xobs.io>
Perform blank checks with the `run_blank_check()` command. Signed-off-by: Sean Cross <sean@xobs.io>
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Add blank_check to flash algorithms. This is code that runs on the target, and is used for checking whether flash is blank or not on parts where the blank status isn't a simple pattern. This is common on ECC parts, where frequently a blank flash isn't even valid.