freebsd-dev/stand/uboot/devicename.c
Warner Losh 5740057b43 stand/uboot: Explain why we test for NULL here
Most parsedev routines assume that idev is non-null and can always be
set. Since we break from this pattern in uboot, explain why in a
comment. devparse was invented to put a lot of common code in one place
and to simplify the archsw.arch_getdev code and any dv_parsedev code
called. However, uboot couldn't use devparse at the time because its
device naming scheme slightly different parsing. So, we still use
uboot_parsedev directly from uboot_getdev where dev could be NULL. Add a
comment to this effect.

The match functionality added for ofw likely could be used to clean up
the multiple kludges that are here for uboot's device naming differences
with the normal boot loader. This work will wait for the future.

Sponsored by:		Netflix
Reviewed by:		kevans
Differential Revision:	https://reviews.freebsd.org/D38042
2023-01-13 14:22:38 -07:00

183 lines
4.6 KiB
C

/*-
* Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <stand.h>
#include <string.h>
#include "bootstrap.h"
#include "disk.h"
#include "libuboot.h"
static int uboot_parsedev(struct uboot_devdesc **dev, const char *devspec,
const char **path);
/*
* Point (dev) at an allocated device specifier for the device matching the
* path in (devspec). If it contains an explicit device specification,
* use that. If not, use the default device.
*/
int
uboot_getdev(void **vdev, const char *devspec, const char **path)
{
struct uboot_devdesc **dev = (struct uboot_devdesc **)vdev;
int rv;
/*
* If it looks like this is just a path and no
* device, go with the current device.
*/
if ((devspec == NULL) || (devspec[0] == '/') ||
(strchr(devspec, ':') == NULL)) {
if (((rv = uboot_parsedev(dev, getenv("currdev"), NULL)) == 0)
&& (path != NULL))
*path = devspec;
return(rv);
}
/*
* Try to parse the device name off the beginning of the devspec.
*/
return (uboot_parsedev(dev, devspec, path));
}
/*
* Point (dev) at an allocated device specifier matching the string version
* at the beginning of (devspec). Return a pointer to the remaining
* text in (path).
*
* In all cases, the beginning of (devspec) is compared to the names
* of known devices in the device switch, and then any following text
* is parsed according to the rules applied to the device type.
*
* For disk-type devices, the syntax is:
*
* disk<unit>[<partition>]:
*
*/
static int
uboot_parsedev(struct uboot_devdesc **dev, const char *devspec,
const char **path)
{
struct uboot_devdesc *idev;
struct devsw *dv;
char *cp;
const char *np;
int i, unit, err;
/* minimum length check */
if (strlen(devspec) < 2)
return(EINVAL);
/* look for a device that matches */
for (i = 0, dv = NULL; devsw[i] != NULL; i++) {
if (!strncmp(devspec, devsw[i]->dv_name,
strlen(devsw[i]->dv_name))) {
dv = devsw[i];
break;
}
}
if (dv == NULL)
return(ENOENT);
idev = malloc(sizeof(struct uboot_devdesc));
err = 0;
np = (devspec + strlen(dv->dv_name));
switch(dv->dv_type) {
case DEVT_NONE:
break;
#ifdef LOADER_DISK_SUPPORT
case DEVT_DISK:
free(idev);
err = disk_parsedev((struct devdesc **)&idev, devspec, path);
if (err != 0)
goto fail;
break;
#endif
case DEVT_NET:
unit = 0;
if (*np && (*np != ':')) {
/* get unit number if present */
unit = strtol(np, &cp, 0);
if (cp == np) {
err = EUNIT;
goto fail;
}
}
if (*cp && (*cp != ':')) {
err = EINVAL;
goto fail;
}
idev->dd.d_unit = unit;
if (path != NULL)
*path = (*cp == 0) ? cp : cp + 1;
break;
default:
err = EINVAL;
goto fail;
}
idev->dd.d_dev = dv;
/*
* dev can be NULL, since uboot_getdev calls us directly, rather than via
* dv_parsedev in devparse() which otherwise ensures that it can't be NULL.
*/
if (dev == NULL) {
free(idev);
} else {
*dev = idev;
}
return (0);
fail:
free(idev);
return (err);
}
/*
* Set currdev to suit the value being supplied in (value).
*/
int
uboot_setcurrdev(struct env_var *ev, int flags, const void *value)
{
struct uboot_devdesc *ncurr;
int rv;
if ((rv = uboot_parsedev(&ncurr, value, NULL)) != 0)
return (rv);
free(ncurr);
return (mount_currdev(ev, flags, value));
}