liminix

commit 63f034e3625f45f46716ff72eafd229362cae5f4
parent 6971d03520a4ebd3c33f3da6f01438608e3d560d
Author: Daniel Barlow <dan@telent.net>
Date:   Sun,  7 Jan 2024 23:52:01 +0000

preinit: parse rootflags= in kernel command line

Diffstat:
A
pkgs/preinit/opts.h
 | 
7
+++++++
M
pkgs/preinit/parseopts.c
 | 
96
++++++++++++++++++++++++++++++++++++++++++++-----------------------------------
M
pkgs/preinit/preinit.c
 | 
25
++++++++++++++++---------

3 files changed, 77 insertions(+), 51 deletions(-)
diff --git a/pkgs/preinit/opts.h b/pkgs/preinit/opts.h
@@ -0,0 +1,7 @@
+struct root_opts {
+    char *device;
+    char *fstype;
+    char *mount_opts;
+};
+
+void parseopts(char * cmdline, struct root_opts *opts);
diff --git a/pkgs/preinit/parseopts.c b/pkgs/preinit/parseopts.c
@@ -3,6 +3,9 @@
 #include <string.h>
 #include <unistd.h>
 
+#include "opts.h"
+
+
 static int begins_with(char * str, char * prefix)
 {
 	while(*prefix) {
@@ -42,29 +45,31 @@ char * pr_u32(int32_t input) {
 	return NULL;
 }
 
+static char *eat_word(char *p)
+{
+    while(*p && (*p != ' ')) p++;
+
+    if(*p) {
+	*p = '\0';
+	p++;
+    };
+    return p;
+}
 
-void parseopts(char * cmdline, char **root, char **rootfstype) {
-    *root = 0;
-    *rootfstype = 0;
+static char * eat_param(char *p, char *param_name, char **out)
+{
+    if(begins_with(p, param_name)) {
+	*out = p + strlen(param_name);
+	p = eat_word(p);
+    };
+    return p;
+}
 
+void parseopts(char * cmdline, struct root_opts *opts) {
     for(char *p = cmdline; *p; p++) {
-	if(begins_with(p, "root=")) {
-	    *root = p + strlen("root=");
-	    while(*p && (*p != ' ')) p++;
-
-	    if(*p) {
-		*p = '\0';
-		p++;
-	    };
-	};
-	if(begins_with(p, "rootfstype=")) {
-	    *rootfstype = p + strlen("rootfstype=");
-	    while(*p && (*p != ' ')) p++;
-	    if(*p) {
-		*p = '\0';
-		p++;
-	    };
-	};
+	p = eat_param(p, "root=", &(opts->device));
+	p = eat_param(p, "rootfstype=", &(opts->fstype));
+	p = eat_param(p, "rootflags=", &(opts->mount_opts));
     };
 }
 
@@ -83,45 +88,52 @@ void parseopts(char * cmdline, char **root, char **rootfstype) {
 
 int main()
 {
-    char * root = "/dev/hda1";
-    char * rootfstype = "xiafs";
+    struct root_opts opts = {
+	.device = "/dev/hda1",
+	.fstype = "xiafs",
+	.mount_opts = NULL
+    };
     char *buf;
 
-    // finds root= and rootfstype= options
-    buf = strdup("liminix console=ttyS0,115200 panic=10 oops=panic init=/bin/init loglevel=8 root=/dev/ubi0_4 rootfstype=ubifs fw_devlink=off mtdparts=phram0:18M(rootfs) phram.phram=phram0,0x40400000,18874368,65536 root=/dev/mtdblock0 foo");
-    parseopts(buf, &root, &rootfstype);
-    expect_equal(root, "/dev/mtdblock0");
-    expect_equal(rootfstype, "ubifs");
+    // finds root= rootfstype= rootopts= options
+    buf = strdup("liminix console=ttyS0,115200 panic=10 oops=panic init=/bin/init loglevel=8 root=/dev/ubi0_4 rootfstype=ubifs rootflags=subvol=1 fw_devlink=off mtdparts=phram0:18M(rootfs) phram.phram=phram0,0x40400000,18874368,65536 root=/dev/mtdblock0 foo");
+    memset(&opts, '\0', sizeof opts); parseopts(buf, &opts);
+    expect_equal(opts.device, "/dev/mtdblock0");
+    expect_equal(opts.fstype, "ubifs");
+    expect_equal(opts.mount_opts, "subvol=1");
 
     // in case of duplicates, chooses the latter
     // also: works if the option is end of string
     buf = strdup("liminix console=ttyS0,115200 panic=10 oops=panic init=/bin/init loglevel=8 root=/dev/ubi0_4 rootfstype=ubifs fw_devlink=off mtdparts=phram0:18M(rootfs) phram.phram=phram0,0x40400000,18874368,65536 root=/dev/mtdblock0");
-    parseopts(buf, &root, &rootfstype);
-    expect_equal(root, "/dev/mtdblock0");
-    expect_equal(rootfstype, "ubifs");
+    memset(&opts, '\0', sizeof opts); parseopts(buf, &opts);
+    expect_equal(opts.device, "/dev/mtdblock0");
+    expect_equal(opts.fstype, "ubifs");
 
     // options may appear in either order
     buf = strdup("liminix fw_devlink=off root=/dev/hda1 rootfstype=ubifs  foo");
-    parseopts(buf, &root, &rootfstype);
-    expect_equal(root, "/dev/hda1");
-    expect_equal(rootfstype, "ubifs");
+    memset(&opts, '\0', sizeof opts); parseopts(buf, &opts);
+    expect_equal(opts.device, "/dev/hda1");
+    expect_equal(opts.fstype, "ubifs");
 
     buf = strdup("liminix rootfstype=ubifs fw_devlink=off root=/dev/hda1 foo");
-    parseopts(buf, &root, &rootfstype);
-    expect_equal(rootfstype, "ubifs");
-    expect_equal(root, "/dev/hda1");
+    memset(&opts, '\0', sizeof opts); parseopts(buf, &opts);
+    expect_equal(opts.fstype, "ubifs");
+    expect_equal(opts.device, "/dev/hda1");
 
     // provides NULL for missing options
     buf = strdup("liminix rufustype=ubifs fw_devlink=off foot=/dev/hda1");
-    parseopts(buf, &root, &rootfstype);
-    if(rootfstype) die("expected null rootfstype, got \"%s\"", rootfstype);
-    if(root) die("expected null root, got \"%s\"", root);
+    memset(&opts, '\0', sizeof opts);  parseopts(buf, &opts);
+
+    if(opts.fstype) die("expected null rootfstype, got \"%s\"", opts.fstype);
+    if(opts.device) die("expected null root, got \"%s\"", opts.device);
+    if(opts.mount_opts) die("expected null mount_opts, got \"%s\"", opts.mount_opts);
 
     // provides empty strings for empty options
     buf = strdup("liminix rootfstype= fw_devlink=off root= /dev/hda1");
-    parseopts(buf, &root, &rootfstype);
-    if(strlen(rootfstype)) die("expected empty rootfstype, got \"%s\"", rootfstype);
-    if(strlen(root)) die("expected null root, got \"%s\"", root);
+    memset(&opts, '\0', sizeof opts);  parseopts(buf, &opts);
+
+    if(strlen(opts.fstype)) die("expected empty rootfstype, got \"%s\"", opts.fstype);
+    if(strlen(opts.device)) die("expected null root, got \"%s\"", opts.device);
 
     expect_equal("01", pr_u32(1));
     expect_equal("ab", pr_u32(0xab));
diff --git a/pkgs/preinit/preinit.c b/pkgs/preinit/preinit.c
@@ -10,7 +10,7 @@
 
 #include <asm/setup.h>		/* for COMMAND_LINE_SIZE */
 
-void parseopts(char * cmdline, char **root, char **rootfstype);
+#include "opts.h"
 
 #define ERR(x) write(2, x, strlen(x))
 #define AVER(c) do { if(c < 0) { ERR("failed: "  #c ": error=0x" ); pr_u32(errno); ERR("\n"); } } while(0)
@@ -49,8 +49,11 @@ char buf[COMMAND_LINE_SIZE];
 
 int main(int argc, char *argv[], char *envp[])
 {
-    char *rootdevice = 0;
-    char *rootfstype = 0;
+    struct root_opts opts = {
+	.device = NULL,
+	.fstype = NULL,
+	.mount_opts = NULL
+    };
 
     write(1, banner, strlen(banner));
 
@@ -73,16 +76,20 @@ int main(int argc, char *argv[], char *envp[])
 	ERR("failed: open(\"/proc/cmdline\")\n");
 	die();
     }
-    parseopts(buf, &rootdevice, &rootfstype);
+    parseopts(buf, &opts);
 
-    if(rootdevice) {
-	if(!rootfstype) rootfstype = "jffs2"; /* backward compatibility */
+    if(opts.device) {
+	if(!opts.fstype) opts.fstype = "jffs2"; /* backward compatibility */
 	write(1, "rootdevice ", 11);
-	write(1, rootdevice, strlen(rootdevice));
+	write(1, opts.device, strlen(opts.device));
 	write(1, " (", 2);
-	write(1, rootfstype, strlen(rootfstype));
+	write(1, opts.fstype, strlen(opts.fstype));
+	if(opts.mount_opts) {
+	    write(1, ", opts=", 6);
+	    write(1, opts.mount_opts, strlen(opts.mount_opts));
+	}
 	write(1, ")\n", 2);
-	AVER(mount(rootdevice, "/target/persist", rootfstype, 0, NULL));
+	AVER(mount(opts.device, "/target/persist", opts.fstype, 0, opts.mount_opts));
 	AVER(mount("/target/persist/nix", "/target/nix",
 		   "bind", MS_BIND, NULL));