Re: [PATCH v2] x86, boot: add hex output for debugging

[Joe Perches <joe@perches.com>]

On Fri, 2014-10-31 at 16:45 -0700, Josh Triplett wrote:
> I don't think we need the full generality of printf in the decompression
> stub.  I prefer Kees' patch, though I'd still like to see __puthex made
> conditional.

Maybe use a statement expression macro instead?
Something like this could emit the right number of bits for any type

#define __puthex(val)							\
({									\
	typeof(val) value = val;					\
	char alpha[2] = {};						\
	int bits;							\
									\
	__putstr("0x");							\
	for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {	\
		int digit = (value >> bits) & 0xf;			\
									\
		if (digit < 10)						\
			alpha[0] = '0' + digit;				\
		else							\
			alpha[0] = 'a' + (digit - 10);			\
									\
		__putstr(alpha);					\
	}								\
})