Attie's printf() / printk() Support Macros

These are intended only for development purposes, and are not considered suitable for use in production-ready code. This header file should perform correctly when used from within all of U-Boot, the Linux kernel, Zephyr, as well as userspace.

Effort has been made to reduce the processing required at run-time, in an attempt at reducing unwanted side effects.

Usage

See example.c for example usage, and example.log for the expected output.

NOTE: GCC's -fmacro-prefix-map argument can be useful for reducing the output length or adding concise context.

The example application can be built and run by running make run.

Configuration

• PK_LEVEL - Provide an output level (Kernel and U-Boot only)
  • Default: KERN_INFO
• PK_FUNC(fmt, args...) - Provides a usable printf-like function that can be called to produce output.
  • Userspace default: fprintf(stderr, fmt "\n", ##args)
  • Kernel default: printk(PK_LEVEL fmt, ##args)
  • U-Boot default: printk(PK_LEVEL fmt "\n", ##args)
• PK_TAG - Resolve to a string literal, that will be at the beginning of every output line.
  • Default: "ATTIE"
• PK_DUMP_WIDTH - Resolves to an integer literal, that will alter the width of the hex dump output.
  • Default: 16

Functions

General

• PK() - A quick and easy notice that the execution path traversed this line.
• PKS(str) - The same as PK(), but includes a static string.
• PKF(fmt, args...) - The same as PK(), but permits a fully-formed format string and associated arguments.
• PKV(fmt, var, ...) - Generates output with the variable's name and value, formatted by fmt.
• PKVS(struct, fmt, member, ...) - Generates output for the struct's members, formatted by fmt.
• PKE(fmt, args...) - The same as PKF(), but with the value of errno and relevant string description.

Timing

• PKTSTART(ts) - Take the current system time, effectively starting a timer.
• PKTSTAMP(fmt, args...) - Generate output with the current system time.
• PKTDIFF(ts, fmt, args...) - Output the time since ts was captured by PKTSTART().
• PKTACC(ts, acc, fmt, args...) - Accumulate the time since ts was captured into acc, and output the running total.
• PKTRATE(ts, n, fmt, args...) - Calculate the event rate, based on the time since ts was captured, and n items processed.
• PKTRAW(ts) - Just print the given timestamp, perhaps as acquired by other means.
• PKTRAWS(ts, str), PKTRAWF(ts, fmt, args...) - Equivelant to PKS() and PKF() respectively.

Dump

• PKDUMP(data, len, fmt, args...) - Output the given format string, followed by the memory size and location, and finally a hex dump of this memory.
• PKLINES(data, len, fmt, args...) - Output the given format string, followed by the memory size and location, and finally a block of text.