From 63f034e3625f45f46716ff72eafd229362cae5f4 Mon Sep 17 00:00:00 2001 From: Daniel Barlow Date: Sun, 7 Jan 2024 23:52:01 +0000 Subject: [PATCH] preinit: parse rootflags= in kernel command line --- pkgs/preinit/opts.h | 7 +++ pkgs/preinit/parseopts.c | 96 ++++++++++++++++++++++------------------ pkgs/preinit/preinit.c | 25 +++++++---- 3 files changed, 77 insertions(+), 51 deletions(-) create mode 100644 pkgs/preinit/opts.h diff --git a/pkgs/preinit/opts.h b/pkgs/preinit/opts.h new file mode 100644 index 0000000..d2b9eac --- /dev/null +++ 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 index 868fd52..7dea032 100644 --- a/pkgs/preinit/parseopts.c +++ b/pkgs/preinit/parseopts.c @@ -3,6 +3,9 @@ #include #include +#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++; -void parseopts(char * cmdline, char **root, char **rootfstype) { - *root = 0; - *rootfstype = 0; + if(*p) { + *p = '\0'; + p++; + }; + return p; +} +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 index 182edd1..8ad7ca7 100644 --- a/pkgs/preinit/preinit.c +++ b/pkgs/preinit/preinit.c @@ -10,7 +10,7 @@ #include /* 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));