# SAMD51 Thing Pluse Bootloader cannot load code larger than 496k

**URL:** <https://community.sparkfun.com/t/samd51-thing-pluse-bootloader-cannot-load-code-larger-than-496k/46880>\
**Category:** Development Boards\
**Tags:** samd\
**Created:** [January 30, 2024, 12:38pm UTC](https://community.sparkfun.com/t/samd51-thing-pluse-bootloader-cannot-load-code-larger-than-496k/46880 "2024-01-30T12:38:13Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![robert-hh](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/robert-hh/32/2916_2.png) [@robert-hh](https://community.sparkfun.com/u/robert-hh)\
**Post date:** [January 30, 2024, 12:38pm UTC](https://community.sparkfun.com/t/samd51-thing-pluse-bootloader-cannot-load-code-larger-than-496k/46880/1 "2024-01-30T12:38:13Z")

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The bootloader seems to refuse loading code in address ranges \>= 0x80000. If the binary size of the code exceeds 496k, the loading address exceeds 0x80000 and the code will not run. The code can be loaded successfully using a JLInk adapter, so it’s not a problem of the MCU, not being able to run code from that address space.

Is that problem known, and is there a fix for it, like an updated bootloader?

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**Author:** ![TS-Russell](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/ts-russell/32/6092_2.png) [@TS-Russell](https://community.sparkfun.com/u/TS-Russell)\
**Post date:** [January 30, 2024, 7:55pm UTC](https://community.sparkfun.com/t/samd51-thing-pluse-bootloader-cannot-load-code-larger-than-496k/46880/2 "2024-01-30T19:55:58Z")

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Create an issue here [https://github.com/sparkfun/SAMD51\_Thin … is%3Aissue](https://github.com/sparkfun/SAMD51_Thing_Plus/issues?q=is%3Aopen+is%3Aissue) to alert the engineering team 🙂

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**Author:** ![robert-hh](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/robert-hh/32/2916_2.png) [@robert-hh](https://community.sparkfun.com/u/robert-hh)\
**Post date:** [January 30, 2024, 9:05pm UTC](https://community.sparkfun.com/t/samd51-thing-pluse-bootloader-cannot-load-code-larger-than-496k/46880/3 "2024-01-30T21:05:44Z")

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Did so, thanks. Just a personal question: do you use the user name scruss in the MicroPython forum/repository?

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<div class="post-metadata">

**Author:** ![robert-hh](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/robert-hh/32/2916_2.png) [@robert-hh](https://community.sparkfun.com/u/robert-hh)\
**Post date:** [February 1, 2024, 9:38pm UTC](https://community.sparkfun.com/t/samd51-thing-pluse-bootloader-cannot-load-code-larger-than-496k/46880/4 "2024-02-01T21:38:32Z")

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It seems that with the firmware supplied in PR #2 the problem is gone. The board I tested had bootloader v2.0.0-34, dated Mar 20, 2019. Link: [https://github.com/sparkfun/SAMD51\_Thing\_Plus/pull/2](https://github.com/sparkfun/SAMD51_Thing_Plus/pull/2)