Re: [PATCH v3 01/17] cmdline: Add generic function to build command line.
From: Rob Herring <robh@kernel.org>
Date: 2021-03-26 15:43:33
Also in:
linux-arch, linux-arm-kernel, linux-devicetree, linux-mips, linux-riscv, linux-sh, lkml, sparclinux
On Fri, Mar 26, 2021 at 7:44 AM Christophe Leroy [off-list ref] wrote:
This code provides architectures with a way to build command line based on what is built in the kernel and what is handed over by the bootloader, based on selected compile-time options.
Note that I have this patch pending: https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20210316193820.3137-1-alex@ghiti.fr/ It's going to need to be adapted for this. I've held off applying to see if this gets settled.
quoted hunk ↗ jump to hunk
Signed-off-by: Christophe Leroy <redacted> --- v3: - Addressed comments from Will - Added capability to have src == dst --- include/linux/cmdline.h | 57 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 include/linux/cmdline.hdiff --git a/include/linux/cmdline.h b/include/linux/cmdline.h new file mode 100644 index 000000000000..dea87edd41be --- /dev/null +++ b/include/linux/cmdline.h@@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_CMDLINE_H +#define _LINUX_CMDLINE_H + +#include <linux/string.h> + +/* Allow architectures to override strlcat, powerpc can't use strings so early */ +#ifndef cmdline_strlcat +#define cmdline_strlcat strlcat +#endif + +/* + * This function will append or prepend a builtin command line to the command + * line provided by the bootloader. Kconfig options can be used to alter + * the behavior of this builtin command line. + * @dst: The destination of the final appended/prepended string. + * @src: The starting string or NULL if there isn't one. + * @len: the length of dest buffer. + */ +static __always_inline void __cmdline_build(char *dst, const char *src, size_t len) +{ + if (!len || src == dst) + return; + + if (IS_ENABLED(CONFIG_CMDLINE_FORCE) || !src) { + dst[0] = 0; + cmdline_strlcat(dst, CONFIG_CMDLINE, len); + return; + } + + if (dst != src) + dst[0] = 0; + + if (IS_ENABLED(CONFIG_CMDLINE_PREPEND)) + cmdline_strlcat(dst, CONFIG_CMDLINE " ", len); + + cmdline_strlcat(dst, src, len); + + if (IS_ENABLED(CONFIG_CMDLINE_EXTEND))
Should be APPEND.
+ cmdline_strlcat(dst, " " CONFIG_CMDLINE, len);
+}
+
+#define cmdline_build(dst, src, len) do { \Perhaps a comment why we need this to be a define.
+ char *__c_dst = (dst); \
+ const char *__c_src = (src); \
+ \
+ if (__c_src == __c_dst) { \
+ static char __c_tmp[COMMAND_LINE_SIZE] __initdata = ""; \
+ \
+ cmdline_strlcat(__c_tmp, __c_src, COMMAND_LINE_SIZE); \
+ __cmdline_build(__c_dst, __c_tmp, (len)); \
+ } else { \
+ __cmdline_build(__c_dst, __c_src, (len)); \
+ } \
+} while (0)
+
+#endif /* _LINUX_CMDLINE_H */
--
2.25.0