| Sysop: | Amessyroom |
|---|---|
| Location: | Fayetteville, NC |
| Users: | 40 |
| Nodes: | 6 (0 / 6) |
| Uptime: | 09:43:30 |
| Calls: | 291 |
| Files: | 910 |
| Messages: | 76,420 |
On Tue, 17 Sep 2024 17:21:36 +0100, The Natural Philosopher ><tnp@invalid.invalid> wrote:
On 17/09/2024 17:09, john larkin wrote:
On Tue, 17 Sep 2024 11:07:17 +0100, The Natural Philosopher
<tnp@invalid.invalid> wrote:
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board; >>>>> if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible >>>>> to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long >>>>> push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
Resetting is done by pulling the power.
The point is that if you do power up with the button pressed, you wipe >>>> the entire FLASH RAM I think.
My Pi guy verifies that entering boot mode doesn't change the contents
of flash. Power cycle and things run like before.
You had me worried!
Really?
I guess whenever I entered that mode it was to download fresh code...
It looks like a USB memory stick. You can delete or add files if you
want.
It boots CPU 0 (the one we call Alice) from a file with the extension
.UL2
Why .UL2 one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU.
An FPGA bitstream file. A prototype calibration table. A README file
to explain everything in plain English.
If you copy a bunch of files into the flash, Windows will lie about
what's there, but there is really only one. If you disconnect the USB
cable and reconnect, Windows will show the one file.
On Tue, 17 Sep 2024 17:21:36 +0100, The Natural Philosopher <tnp@invalid.invalid> wrote:
On 17/09/2024 17:09, john larkin wrote:
On Tue, 17 Sep 2024 11:07:17 +0100, The Natural Philosopher
<tnp@invalid.invalid> wrote:
On 17/09/2024 03:58, john larkin wrote:
The RP2040 has a cool mode where it can be made to boot up with theThats' what my PICO powered thermostats have. For the onboard button though
USB port looking like a memory stick. That's great for software
installs or upgrades. The Pico board has a BOOT button on the board; >>>>> if the pico is powered up with the button pushed, it goes into that
boot mode.
But if I have a product (actually a family of products) in a nice
aluminum box, a user would have to remove the top cover, remove all
power sources (there can be three), and hold the button down while
reconnecting power.
Some of my customers also want to lock a box such that it's impossible >>>>> to write to any nonvolatile memory while it's in a secure area.
So here's an idea: a small hole in the box allows a toothpick or a
paper clip to push a button. A short push is a regular reset. A long >>>>> push is a memory-stick mode boot. We can have a rotary switch LOCK
hole too.
Resetting is done by pulling the power.
The point is that if you do power up with the button pressed, you wipe >>>> the entire FLASH RAM I think.
My Pi guy verifies that entering boot mode doesn't change the contents
of flash. Power cycle and things run like before.
You had me worried!
Really?
I guess whenever I entered that mode it was to download fresh code...
It looks like a USB memory stick. You can delete or add files if you
want.
It boots CPU 0 (the one we call Alice) from a file with the extension
.UL2
Why .UL2 one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU.
An FPGA bitstream file. A prototype calibration table. A README file
to explain everything in plain English.
On 9/18/24 00:33, john larkin wrote:
It looks like a USB memory stick. You can delete or add files if you
want.
It boots CPU 0 (the one we call Alice) from a file with the extension
.UL2
Why .UL2 one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU.
An FPGA bitstream file. A prototype calibration table. A README file
to explain everything in plain English.
sure it's not UF2?
https://github.com/microsoft/uf2
On 19/09/2024 23:09, Lasse Langwadt wrote:
On 9/18/24 00:33, john larkin wrote:
It looks like a USB memory stick. You can delete or add files if you
want.
It boots CPU 0 (the one we call Alice) from a file with the extension
.UL2
Why .UL2 one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU.
An FPGA bitstream file. A prototype calibration table. A README file
to explain everything in plain English.
sure it's not UF2?
https://github.com/microsoft/uf2
Definitely uf2 here.
And no, you cannot 'delete or add files' to it.
The action of pretending to download a uf2 file into what appears to be
an empty drive, erases everything on it and programs the flash.
There are no visible files to delete.
In comp.sys.raspberry-pi The Natural Philosopher <tnp@invalid.invalid> wrote: >> On 19/09/2024 23:09, Lasse Langwadt wrote:
On 9/18/24 00:33, john larkin wrote:Definitely uf2 here.
It looks like a USB memory stick. You can delete or add files if you
want.
It boots CPU 0 (the one we call Alice) from a file with the extension
.UL2
Whyáá .UL2áá one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU.
An FPGA bitstream file. A prototype calibration table. A README file
to explain everything in plain English.
sure it's not UF2?
https://github.com/microsoft/uf2
And no, you cannot 'delete or add files' to it.
The action of pretending to download a uf2 file into what appears to be
an empty drive, erases everything on it and programs the flash.
There are no visible files to delete.
Neat. So basically you throw some files at it, which causes a series of >block writes. UF2 picks out specially tagged block writes and uses that to >program the flash. It doesn't actually care what other stuff is written to >the flash as it ignores all of that, so it doesn't care about all the FAT >stuff or whatever junk your OS decides to put on there.
Means you can write any kind of files to it and it'll only pay attention to >the specific tagged blocks. If the OS is happy to cache the medium (as many >do) you could maybe even reformat it as some other filesystem like NTFS and >it would still handle writing the UF2 file correctly.
Theo
On 20 Sep 2024 11:30:13 +0100 (BST), Theo
<theom+news@chiark.greenend.org.uk> wrote:
In comp.sys.raspberry-pi The Natural Philosopher <tnp@invalid.invalid> wrote:
On 19/09/2024 23:09, Lasse Langwadt wrote:
On 9/18/24 00:33, john larkin wrote:Definitely uf2 here.
It looks like a USB memory stick. You can delete or add files if you >>>>> want.
It boots CPU 0 (the one we call Alice) from a file with the extension >>>>> .UL2
Why .UL2 one wonders.
We'll put a bunch of files into the flash. Code for Bob, the 2nd CPU. >>>>> An FPGA bitstream file. A prototype calibration table. A README file >>>>> to explain everything in plain English.
sure it's not UF2?
https://github.com/microsoft/uf2
And no, you cannot 'delete or add files' to it.
The action of pretending to download a uf2 file into what appears to be
an empty drive, erases everything on it and programs the flash.
There are no visible files to delete.
Neat. So basically you throw some files at it, which causes a series of
block writes. UF2 picks out specially tagged block writes and uses that to >> program the flash. It doesn't actually care what other stuff is written to >> the flash as it ignores all of that, so it doesn't care about all the FAT
stuff or whatever junk your OS decides to put on there.
Means you can write any kind of files to it and it'll only pay attention to >> the specific tagged blocks. If the OS is happy to cache the medium (as many >> do) you could maybe even reformat it as some other filesystem like NTFS and >> it would still handle writing the UF2 file correctly.
Theo
My Pi guy says that you can only write one file, and the act of
writing that file wipes anything that was there before. So the flash
probably doesn't have a file structure, and the USB memory-stick write
is, well, a sort of cheap trick.
That's workable, if inelegant. We can pack everything we need into
that one big file and users can upgrade box code in the field pretty
easily.