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Add --esp/-E argument to print the currently booted ESP

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Add code to decode the BootCurrent and BootXXXX variable it points at
to deduce the ESP used to boot the system. By default, it prints the
path to that device. With --unix-path (-p) it will instead print the
current mount point for the ESP, if any (or an error). With
--device-path (-d) it wil print the UEFI device path for the ESP.

Note: This is the best guess based on the UEFI variables. If the ESP
is part of a gmirror, etc, that won't be reported. If by some weird
chance there was a complicated series of chain boots, this may not be
what you want. For setups that don't add layers on top of the raw
devices, it is accurate.

Differential Revision: https://reviews.freebsd.org/D22432
This commit is contained in:
Warner Losh 2019-11-20 23:58:36 +00:00
parent 9af6c78cd4
commit 1cdb8eb8fe
2 changed files with 104 additions and 1 deletions
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20
usr.sbin/efibootmgr/efibootmgr.8
View File

@ -49,6 +49,11 @@
.Op Fl b Ar bootnum
.Op Fl k Ar kernel
.Op Fl L Ar label
.Op Fl e Ar env
.Nm
.Fl E
.Op Fl d
.Op Fl p
.Nm
.Fl n
.Fl b Ar bootnum
@ -111,6 +116,21 @@ Create a new
variable.
.It Fl D -dry-run
Process but do not change any variables.
.It Fl E -esp
Print the
.Fx
path to the ESP device, derived from the EFI variables
.Va BootCurrent
and
.Va BootXXXX .
This is the ESP partition used by UEFI to boot the current
instance of the system.
If
.Fl d -device-path
is specified, the UEFI device path to the ESP is reported instead.
If
.Fl p -unix-path
is specified, the mount point of the ESP is reported instead.
.It Fl k -kernel Ar kernel
The path to and name of the kernel.
.It Fl l -loader Ar loader

85
usr.sbin/efibootmgr/efibootmgr.c
View File

@ -81,6 +81,8 @@ typedef struct _bmgr_opts {
bool delete_bootnext;
bool del_timeout;
bool dry_run;
bool device_path;
bool esp_device;
bool has_bootnum;
bool once;
int cp_src;
@ -89,6 +91,7 @@ typedef struct _bmgr_opts {
bool set_inactive;
bool set_timeout;
int timeout;
bool unix_path;
bool verbose;
} bmgr_opts_t;
@ -103,14 +106,17 @@ static struct option lopts[] = {
{"del-timout", no_argument, NULL, 'T'},
{"delete", no_argument, NULL, 'B'},
{"delete-bootnext", no_argument, NULL, 'N'},
{"device-path", no_argument, NULL, 'd'},
{"dry-run", no_argument, NULL, 'D'},
{"env", required_argument, NULL, 'e'},
{"esp", no_argument, NULL, 'E'},
{"help", no_argument, NULL, 'h'},
{"kernel", required_argument, NULL, 'k'},
{"label", required_argument, NULL, 'L'},
{"loader", required_argument, NULL, 'l'},
{"once", no_argument, NULL, 'O'},
{"set-timeout", required_argument, NULL, 't'},
{"unix-path", no_argument, NULL, 'p'},
{"verbose", no_argument, NULL, 'v'},
{ NULL, 0, NULL, 0}
};
@ -191,7 +197,7 @@ parse_args(int argc, char *argv[])
{
int ch;
while ((ch = getopt_long(argc, argv, "AaBb:C:cDe:hk:L:l:NnOo:Tt:v",
while ((ch = getopt_long(argc, argv, "AaBb:C:cdDe:Ehk:L:l:NnOo:pTt:v",
lopts, NULL)) != -1) {
switch (ch) {
case 'A':
@ -216,10 +222,16 @@ parse_args(int argc, char *argv[])
case 'D': /* should be remove dups XXX */
opts.dry_run = true;
break;
case 'd':
opts.device_path = true;
break;
case 'e':
free(opts.env);
opts.env = strdup(optarg);
break;
case 'E':
opts.esp_device = true;
break;
case 'h':
default:
errx(1, "%s", USAGE);
@ -250,6 +262,9 @@ parse_args(int argc, char *argv[])
free(opts.order);
opts.order = strdup(optarg);
break;
case 'p':
opts.unix_path = true;
break;
case 'T':
opts.del_timeout = true;
break;
@ -906,6 +921,72 @@ handle_timeout(int to)
errx(1, "Can't set Timeout for booting.");
}
static void
report_esp_device(bool do_dp, bool do_unix)
{
uint8_t *data;
size_t size, len;
uint32_t attrs;
int ret;
uint16_t current, fplen;
char *name, *dev, *relpath, *abspath;
uint8_t *walker, *ep;
efi_char *descr;
efidp dp, edp;
char buf[PATH_MAX];
if (do_dp && do_unix)
errx(1, "Can't report both UEFI device-path and Unix path together");
ret = efi_get_variable(EFI_GLOBAL_GUID, "BootCurrent", &data, &size,&attrs);
if (ret < 0)
err(1, "Can't get BootCurrent");
current = le16dec(data);
if (asprintf(&name, "Boot%04X", current) < 0)
err(1, "Can't format boot var\n");
if (efi_get_variable(EFI_GLOBAL_GUID, name, &data, &size, NULL) < 0)
err(1, "Can't retrieve EFI var %s", name);
// First 4 bytes are attribute flags
walker = data;
ep = walker + size;
walker += sizeof(uint32_t);
// Next two bytes are length of the file paths
fplen = le16dec(walker);
walker += sizeof(fplen);
// Next we have a 0 terminated UCS2 string that we know to be aligned
descr = (efi_char *)(intptr_t)(void *)walker;
len = ucs2len(descr); // XXX need to sanity check that len < (datalen - (ep - walker) / 2)
walker += (len + 1) * sizeof(efi_char);
if (walker > ep)
errx(1, "malformed boot variable %s", name);
// Now we have fplen bytes worth of file path stuff
dp = (efidp)walker;
walker += fplen;
edp = (efidp)walker;
if (walker > ep)
errx(1, "malformed boot variable %s", name);
if (do_dp) {
efidp_format_device_path_node(buf, sizeof(buf), dp);
printf("%s\n", buf);
exit(0);
}
if (efivar_device_path_to_unix_path(dp, &dev, &relpath, &abspath) < 0)
errx(1, "Can't convert to unix path");
if (do_unix) {
if (abspath == NULL)
errx(1, "Can't find where %s:%s is mounted",
dev, relpath);
abspath[strlen(abspath) - strlen(relpath) - 1] = '\0';
printf("%s\n", abspath);
} else {
printf("%s\n", dev);
}
free(dev);
free(relpath);
free(abspath);
exit(0);
}
int
main(int argc, char *argv[])
{
@ -938,6 +1019,8 @@ main(int argc, char *argv[])
delete_timeout();
else if (opts.set_timeout)
handle_timeout(opts.timeout);
else if (opts.esp_device)
report_esp_device(opts.device_path, opts.unix_path);
print_boot_vars(opts.verbose);
}