SM6FBQ / HackRF clone - History

Assign names to registers which are used for a single purpose.

This is just to improve readability; there is no change to the code.

Use defines for offsets into SGPIO shadow registers.

This is just to make the SGPIO code less cryptic, and to place
the explanation of the offsets closer to where they are defined.

Move M0 offset and tx variables into a state struct.

These variables are already placed together; this commit just groups
them into a struct and declares this in a new header.

This commit should not result in any change to the firmware binary.
Only the names of symbols are changed.

Remove usb_bulk_buffer.c containing unused variable definition.

This removes the definition of the offset variable,

volatile uint32_t usb_bulk_buffer_offset = 0;

which is actually superfluous. This variable, along with its neighbour
usb_bulk_buffer_tx, is placed explicitly by the linker script. Its type
is defined by the declaration in usb_bulk_buffer.h.

There is no need to define it here, and doing so gives the misleading
impression that its initial value can be changed by modifying this line!

The initialization to zero never actually takes effect, because the
variable is not placed in the .data or .bss sections which are
initialised by the startup code.

The offset and tx variables are both set in set_transceiver_mode
before SGPIO streaming is started, so the M0 code does not use
them uninitialised.

Document purpose and timing of existing M0 code.

This commit does not modify the code; it only updates comments.

Merge pull request #1025 from straithe/updateDocs

Update docs

avoid incorrect syntax highlighting

also remove spaces before '::'s