This patch adds a small printf() version that supports all basic formats. Its intented to be used in U-Boot SPL versions on platforms with very limited internal RAM sizes.
To enable it, just define CONFIG_USE_TINY_PRINTF in your defconfig. This will result in the SPL using this tiny function and the main U-Boot still using the full-blown printf() function. This code was copied from: http://www.sparetimelabs.com/printfrevisited With mostly only coding style related changes so that its checkpatch clean. The size reduction is about 2.5KiB. Here a comparison for the db-mv784mp-gp (Marvell AXP) SPL: Without this patch: 58963 18536 1928 79427 13643 ./spl/u-boot-spl With this patch: 56542 18536 1956 77034 12cea ./spl/u-boot-spl Note: To make it possible to compile tiny-printf.c instead of vsprintf.c when CONFIG_USE_TINY_PRINTF is defined, the functions printf() and vprintf() are moved from common/console.c into vsprintf.c in this patch. Signed-off-by: Stefan Roese <s...@denx.de> Cc: Simon Glass <s...@chromium.org> Cc: Hans de Goede <hdego...@redhat.com> Cc: Tom Rini <tr...@konsulko.com> Cc: Albert Aribaud <albert.u.b...@aribaud.net> --- v2: - Patch split-up into multiple patches - Added comment about supported formats in Kconfig common/console.c | 36 --------------- lib/Kconfig | 10 +++++ lib/Makefile | 7 ++- lib/tiny-printf.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ lib/vsprintf.c | 36 +++++++++++++++ 5 files changed, 182 insertions(+), 37 deletions(-) create mode 100644 lib/tiny-printf.c diff --git a/common/console.c b/common/console.c index cf86b76..2bfd59f 100644 --- a/common/console.c +++ b/common/console.c @@ -535,42 +535,6 @@ void puts(const char *s) } } -int printf(const char *fmt, ...) -{ - va_list args; - uint i; - char printbuffer[CONFIG_SYS_PBSIZE]; - - va_start(args, fmt); - - /* - * For this to work, printbuffer must be larger than - * anything we ever want to print. - */ - i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args); - va_end(args); - - /* Print the string */ - puts(printbuffer); - return i; -} - -int vprintf(const char *fmt, va_list args) -{ - uint i; - char printbuffer[CONFIG_SYS_PBSIZE]; - - /* - * For this to work, printbuffer must be larger than - * anything we ever want to print. - */ - i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args); - - /* Print the string */ - puts(printbuffer); - return i; -} - /* test if ctrl-c was pressed */ static int ctrlc_disabled = 0; /* see disable_ctrl() */ static int ctrlc_was_pressed = 0; diff --git a/lib/Kconfig b/lib/Kconfig index 30e84ed..9d580e4 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -36,6 +36,16 @@ config SYS_VSNPRINTF Thumb-2, about 420 bytes). Enable this option for safety when using sprintf() with data you do not control. +config USE_TINY_PRINTF + bool "Enable tiny printf() version" + help + This option enables a tiny, stripped down printf version. + This should only be used in space limited environments, + like SPL versions with hard memory limits. This version + reduces the code size by about 2.5KiB on armv7. + + The supported format specifiers are %c, %s, %u/%d and %x. + config REGEX bool "Enable regular expression support" default y if NET diff --git a/lib/Makefile b/lib/Makefile index 3eecefa..54b6555 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -79,7 +79,12 @@ obj-y += string.o obj-y += time.o obj-$(CONFIG_TRACE) += trace.o obj-$(CONFIG_LIB_UUID) += uuid.o -obj-y += vsprintf.o obj-$(CONFIG_LIB_RAND) += rand.o +ifeq ($(CONFIG_SPL_BUILD)$(CONFIG_USE_TINY_PRINTF),yy) +obj-y += tiny-printf.o +else +obj-y += vsprintf.o +endif + subdir-ccflags-$(CONFIG_CC_OPTIMIZE_LIBS_FOR_SPEED) += -O2 diff --git a/lib/tiny-printf.c b/lib/tiny-printf.c new file mode 100644 index 0000000..d743a36 --- /dev/null +++ b/lib/tiny-printf.c @@ -0,0 +1,130 @@ +/* + * Tiny printf version for SPL + * + * Copied from: + * http://www.sparetimelabs.com/printfrevisited/printfrevisited.php + * + * Copyright (C) 2004,2008 Kustaa Nyholm + * + * SPDX-License-Identifier: LGPL-2.1+ + */ + +#include <common.h> +#include <stdarg.h> +#include <serial.h> + +static char *bf; +static char buf[12]; +static unsigned int num; +static char uc; +static char zs; + +static void out(char c) +{ + *bf++ = c; +} + +static void out_dgt(char dgt) +{ + out(dgt + (dgt < 10 ? '0' : (uc ? 'A' : 'a') - 10)); + zs = 1; +} + +static void div_out(unsigned int div) +{ + unsigned char dgt = 0; + + num &= 0xffff; /* just for testing the code with 32 bit ints */ + while (num >= div) { + num -= div; + dgt++; + } + + if (zs || dgt > 0) + out_dgt(dgt); +} + +int printf(const char *fmt, ...) +{ + va_list va; + char ch; + char *p; + + va_start(va, fmt); + + while ((ch = *(fmt++))) { + if (ch != '%') { + putc(ch); + } else { + char lz = 0; + char w = 0; + + ch = *(fmt++); + if (ch == '0') { + ch = *(fmt++); + lz = 1; + } + + if (ch >= '0' && ch <= '9') { + w = 0; + while (ch >= '0' && ch <= '9') { + w = (((w << 2) + w) << 1) + ch - '0'; + ch = *fmt++; + } + } + bf = buf; + p = bf; + zs = 0; + + switch (ch) { + case 0: + goto abort; + case 'u': + case 'd': + num = va_arg(va, unsigned int); + if (ch == 'd' && (int)num < 0) { + num = -(int)num; + out('-'); + } + div_out(10000); + div_out(1000); + div_out(100); + div_out(10); + out_dgt(num); + break; + case 'x': + case 'X': + uc = ch == 'X'; + num = va_arg(va, unsigned int); + div_out(0x1000); + div_out(0x100); + div_out(0x10); + out_dgt(num); + break; + case 'c': + out((char)(va_arg(va, int))); + break; + case 's': + p = va_arg(va, char*); + break; + case '%': + out('%'); + default: + break; + } + + *bf = 0; + bf = p; + while (*bf++ && w > 0) + w--; + while (w-- > 0) + putc(lz ? '0' : ' '); + while ((ch = *p++)) + putc(ch); + } + } + +abort: + va_end(va); + return 0; +} diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 4c82837..dd8380b 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -861,6 +861,42 @@ int sprintf(char *buf, const char *fmt, ...) return i; } +int printf(const char *fmt, ...) +{ + va_list args; + uint i; + char printbuffer[CONFIG_SYS_PBSIZE]; + + va_start(args, fmt); + + /* + * For this to work, printbuffer must be larger than + * anything we ever want to print. + */ + i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args); + va_end(args); + + /* Print the string */ + puts(printbuffer); + return i; +} + +int vprintf(const char *fmt, va_list args) +{ + uint i; + char printbuffer[CONFIG_SYS_PBSIZE]; + + /* + * For this to work, printbuffer must be larger than + * anything we ever want to print. + */ + i = vscnprintf(printbuffer, sizeof(printbuffer), fmt, args); + + /* Print the string */ + puts(printbuffer); + return i; +} + static void panic_finish(void) __attribute__ ((noreturn)); static void panic_finish(void) -- 2.6.3 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
