shimun/solo
1
0
Fork 0
Code Issues Pull Requests Releases 1 Wiki Activity

add more clarity

Browse Source
This commit is contained in:
Conor Patrick 2019-11-22 18:12:50 -05:00
parent f6d3744de8
commit 05ab5f9d23
1 changed files with 17 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
docs/solo/porting.md
View File

@ -32,17 +32,29 @@ int main()
`ctaphid_handle_packet(hidmsg);` is the entrance into the HID layer of libsolo, and will buffer packets and pass them `ctaphid_handle_packet(hidmsg);` is the entrance into the HID layer of libsolo, and will buffer packets and pass them
into FIDO2 or U2F layers. into FIDO2 or U2F layers.
Everything in the library is cross-platform, and it makes calls to functions defined Everything in the library is cross-platform, but it needs some functions implemented that are usually
in `fido2/device.h` to do possibly platform specific things. To get the library to compile platform specific. For example, how should libsolo implement an atomic counter? Where should it save state?
and run, you only need to implement one of these functions: `usbhid_send(uint8_t * send)`, which For all of these platform specific functions, the library contains it's own `weak` definition, so the library will compile and run.
is called by the library to send a 64 byte packet over a USB HID endpoint. LibSolo by default will not try to use an atomic
counter or save data persistently -- that needs to be implemented externally.
If you are using libsolo on another platform,
you should take a look at these possibly platform specific functions. They are listed in `fido2/device.h`.
If you'd like to reimplement any of the functions, then simply implement the function and compile normally.
GCC will replace libsolo's `weak` defined functions (everything in `fido2/device.h`) with your functions. By doing this, you
are replacing the function that is used by libsolo.
To get the library to compile
and run, you only need to implement one function for libsolo: `usbhid_send(uint8_t * send)`, which
is called by the library to send a 64 byte packet over a USB HID endpoint. In essence, you are giving
libsolo a function to write to USB.
The rest of the definitions in `fido2/device.h` are not required to compile and run so you can The rest of the definitions in `fido2/device.h` are not required to compile and run so you can
immediately hit the ground running and iterative add what else you need. You'll definitely want immediately hit the ground running and iterative add what else you need. You'll definitely want
to continue implementing other functions in `fido2/device.h`. For example, no data will be stored to continue implementing other functions in `fido2/device.h`. For example, no data will be stored
persistently until you define how it can be done! persistently until you define how it can be done!
For examples, check out the build for STM32L4 and PC. For examples, check out the build for STM32L4 and PC (check out `pc/device` and `targets/stm32l432/src/device.c`).
If there's something that doesn't work for you -- send a pull request! It's better if we can If there's something that doesn't work for you -- send a pull request! It's better if we can
work together off of the same repo and not fork. work together off of the same repo and not fork.