From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
danielwa@cisco.com, robh@kernel.org,
daniel@gimpelevich.san-francisco.ca.us
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-arch@vger.kernel.org, devicetree@vger.kernel.org
Subject: [PATCH v2 1/7] cmdline: Add generic function to build command line.
Date: Tue, 2 Mar 2021 17:25:17 +0000 (UTC) [thread overview]
Message-ID: <d8cf7979ad986de45301b39a757c268d9df19f35.1614705851.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1614705851.git.christophe.leroy@csgroup.eu>
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.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
include/linux/cmdline.h | 62 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
create mode 100644 include/linux/cmdline.h
diff --git a/include/linux/cmdline.h b/include/linux/cmdline.h
new file mode 100644
index 000000000000..ae3610bb0ee2
--- /dev/null
+++ b/include/linux/cmdline.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CMDLINE_H
+#define _LINUX_CMDLINE_H
+
+static __always_inline size_t cmdline_strlen(const char *s)
+{
+ const char *sc;
+
+ for (sc = s; *sc != '\0'; ++sc)
+ ; /* nothing */
+ return sc - s;
+}
+
+static __always_inline size_t cmdline_strlcat(char *dest, const char *src, size_t count)
+{
+ size_t dsize = cmdline_strlen(dest);
+ size_t len = cmdline_strlen(src);
+ size_t res = dsize + len;
+
+ /* This would be a bug */
+ if (dsize >= count)
+ return count;
+
+ dest += dsize;
+ count -= dsize;
+ if (len >= count)
+ len = count - 1;
+ memcpy(dest, src, len);
+ dest[len] = 0;
+ return res;
+}
+
+/*
+ * This function will append 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.
+ * @dest: The destination of the final appended/prepended string.
+ * @src: The starting string or NULL if there isn't one. Must not equal dest.
+ * @length: the length of dest buffer.
+ */
+static __always_inline void cmdline_build(char *dest, const char *src, size_t length)
+{
+ if (length <= 0)
+ return;
+
+ dest[0] = 0;
+
+#ifdef CONFIG_CMDLINE
+ if (IS_ENABLED(CONFIG_CMDLINE_FORCE) || !src || !src[0]) {
+ cmdline_strlcat(dest, CONFIG_CMDLINE, length);
+ return;
+ }
+#endif
+ if (dest != src)
+ cmdline_strlcat(dest, src, length);
+#ifdef CONFIG_CMDLINE
+ if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) && sizeof(CONFIG_CMDLINE) > 1)
+ cmdline_strlcat(dest, " " CONFIG_CMDLINE, length);
+#endif
+}
+
+#endif /* _LINUX_CMDLINE_H */
--
2.25.0
next prev parent reply other threads:[~2021-03-02 20:53 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-02 17:25 [PATCH v2 0/7] Improve boot command line handling Christophe Leroy
2021-03-02 17:25 ` Christophe Leroy [this message]
2021-03-03 17:28 ` [PATCH v2 1/7] cmdline: Add generic function to build command line Will Deacon
2021-03-03 17:38 ` Christophe Leroy
2021-03-03 17:46 ` Will Deacon
2021-03-03 17:57 ` Christophe Leroy
2021-03-03 18:16 ` Will Deacon
2021-03-05 11:58 ` Michael Ellerman
2021-03-05 12:49 ` Christophe Leroy
2021-03-05 18:35 ` Segher Boessenkool
2021-03-05 18:33 ` Segher Boessenkool
2021-03-03 17:39 ` Will Deacon
2021-03-02 17:25 ` [PATCH v2 2/7] drivers: of: use cmdline building function Christophe Leroy
2021-03-02 17:25 ` [PATCH v2 3/7] powerpc: convert to generic builtin command line Christophe Leroy
2021-03-02 17:25 ` [PATCH v2 4/7] cmdline: Add capability to prepend the " Christophe Leroy
2021-03-03 18:19 ` Will Deacon
2021-03-02 17:25 ` [PATCH v2 5/7] powerpc: add capability to prepend default " Christophe Leroy
2021-03-02 17:25 ` [PATCH v2 6/7] cmdline: Gives architectures opportunity to use generically defined boot cmdline manipulation Christophe Leroy
2021-03-02 19:30 ` kernel test robot
2021-03-03 17:57 ` Will Deacon
2021-03-25 11:18 ` Christophe Leroy
2021-03-25 19:32 ` Will Deacon
2021-03-26 6:18 ` Christophe Leroy
2021-03-26 6:44 ` Christophe Leroy
2021-03-02 17:25 ` [PATCH v2 7/7] powerpc: use generic CMDLINE manipulations Christophe Leroy
2021-03-02 17:35 ` [PATCH v2 0/7] Improve boot command line handling Daniel Walker
2021-03-02 17:39 ` Christophe Leroy
2021-03-03 2:01 ` Rob Herring
2021-03-03 17:39 ` Daniel Walker
2021-03-03 18:07 ` Christophe Leroy
2021-03-03 18:53 ` Daniel Walker
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=d8cf7979ad986de45301b39a757c268d9df19f35.1614705851.git.christophe.leroy@csgroup.eu \
--to=christophe.leroy@csgroup.eu \
--cc=benh@kernel.crashing.org \
--cc=daniel@gimpelevich.san-francisco.ca.us \
--cc=danielwa@cisco.com \
--cc=devicetree@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=paulus@samba.org \
--cc=robh@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).