freebsd-dev/stand/kboot/main.c
Warner Losh 57f90cf813 kboot: add minmalist init functionality
It is desirable to run kboot as the first program in some LinuxBoot
environments. This is the traditional "pid 1" or "init" program. When
running as pid 1. rovide a minimal environment based on what sysvinit,
u-root, initramfs-tools and other like projects do. We mount /dev, /sys,
/proc, make symlinks from /dev/fd to /dev/proc, and create /tmp, /run,
and /var. We also setup stdin/out/err to the console, set the tty
characteristics of same and block the appropriate signals.

This is indended as an environment that never does a fork/exec. If
that's required, the process groups, session leaders and all things
POSIX terminal handlers will need to be added.

Unlike the general purpose linux projects in this area, no attempt is
made to support very old kernels.

When not pid 1, we skip all of the above.

Sponsored by:		Netflix
Differential Revision:	https://reviews.freebsd.org/D36368
2022-09-01 11:08:24 -06:00

500 lines
12 KiB
C

/*-
* Copyright (C) 2010-2014 Nathan Whitehorn
* 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 ``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 TOOLS GMBH 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 <sys/endian.h>
#include <sys/param.h>
#include <fdt_platform.h>
#include <machine/cpufunc.h>
#include <bootstrap.h>
#include "host_syscall.h"
#include "kboot.h"
struct arch_switch archsw;
extern void *_end;
int kboot_getdev(void **vdev, const char *devspec, const char **path);
ssize_t kboot_copyin(const void *src, vm_offset_t dest, const size_t len);
ssize_t kboot_copyout(vm_offset_t src, void *dest, const size_t len);
ssize_t kboot_readin(readin_handle_t fd, vm_offset_t dest, const size_t len);
int kboot_autoload(void);
uint64_t kboot_loadaddr(u_int type, void *data, uint64_t addr);
static void kboot_kseg_get(int *nseg, void **ptr);
extern int command_fdt_internal(int argc, char *argv[]);
struct region_desc {
uint64_t start;
uint64_t end;
};
static uint64_t
kboot_get_phys_load_segment(void)
{
int fd;
uint64_t entry[2];
static uint64_t load_segment = ~(0UL);
uint64_t val_64;
uint32_t val_32;
struct region_desc rsvd_reg[32];
int rsvd_reg_cnt = 0;
int ret, a, b;
uint64_t start, end;
if (load_segment == ~(0UL)) {
/* Default load address is 0x00000000 */
load_segment = 0UL;
/* Read reserved regions */
fd = host_open("/proc/device-tree/reserved-ranges", O_RDONLY, 0);
if (fd >= 0) {
while (host_read(fd, &entry[0], sizeof(entry)) == sizeof(entry)) {
rsvd_reg[rsvd_reg_cnt].start = be64toh(entry[0]);
rsvd_reg[rsvd_reg_cnt].end =
be64toh(entry[1]) + rsvd_reg[rsvd_reg_cnt].start - 1;
rsvd_reg_cnt++;
}
host_close(fd);
}
/* Read where the kernel ends */
fd = host_open("/proc/device-tree/chosen/linux,kernel-end", O_RDONLY, 0);
if (fd >= 0) {
ret = host_read(fd, &val_64, sizeof(val_64));
if (ret == sizeof(uint64_t)) {
rsvd_reg[rsvd_reg_cnt].start = 0;
rsvd_reg[rsvd_reg_cnt].end = be64toh(val_64) - 1;
} else {
memcpy(&val_32, &val_64, sizeof(val_32));
rsvd_reg[rsvd_reg_cnt].start = 0;
rsvd_reg[rsvd_reg_cnt].end = be32toh(val_32) - 1;
}
rsvd_reg_cnt++;
host_close(fd);
}
/* Read memory size (SOCKET0 only) */
fd = host_open("/proc/device-tree/memory@0/reg", O_RDONLY, 0);
if (fd < 0)
fd = host_open("/proc/device-tree/memory/reg", O_RDONLY, 0);
if (fd >= 0) {
ret = host_read(fd, &entry, sizeof(entry));
/* Memory range in start:length format */
entry[0] = be64toh(entry[0]);
entry[1] = be64toh(entry[1]);
/* Reserve everything what is before start */
if (entry[0] != 0) {
rsvd_reg[rsvd_reg_cnt].start = 0;
rsvd_reg[rsvd_reg_cnt].end = entry[0] - 1;
rsvd_reg_cnt++;
}
/* Reserve everything what is after end */
if (entry[1] != 0xffffffffffffffffUL) {
rsvd_reg[rsvd_reg_cnt].start = entry[0] + entry[1];
rsvd_reg[rsvd_reg_cnt].end = 0xffffffffffffffffUL;
rsvd_reg_cnt++;
}
host_close(fd);
}
/* Sort entries in ascending order (bubble) */
for (a = rsvd_reg_cnt - 1; a > 0; a--) {
for (b = 0; b < a; b++) {
if (rsvd_reg[b].start > rsvd_reg[b + 1].start) {
struct region_desc tmp;
tmp = rsvd_reg[b];
rsvd_reg[b] = rsvd_reg[b + 1];
rsvd_reg[b + 1] = tmp;
}
}
}
/* Join overlapping/adjacent regions */
for (a = 0; a < rsvd_reg_cnt - 1; ) {
if ((rsvd_reg[a + 1].start >= rsvd_reg[a].start) &&
((rsvd_reg[a + 1].start - 1) <= rsvd_reg[a].end)) {
/* We have overlapping/adjacent regions! */
rsvd_reg[a].end =
MAX(rsvd_reg[a].end, rsvd_reg[a + a].end);
for (b = a + 1; b < rsvd_reg_cnt - 1; b++)
rsvd_reg[b] = rsvd_reg[b + 1];
rsvd_reg_cnt--;
} else
a++;
}
/* Find the first free region */
if (rsvd_reg_cnt > 0) {
start = 0;
end = rsvd_reg[0].start;
for (a = 0; a < rsvd_reg_cnt - 1; a++) {
if ((start >= rsvd_reg[a].start) &&
(start <= rsvd_reg[a].end)) {
start = rsvd_reg[a].end + 1;
end = rsvd_reg[a + 1].start;
} else
break;
}
if (start != end) {
uint64_t align = 64UL*1024UL*1024UL;
/* Align both to 64MB boundary */
start = (start + align - 1UL) & ~(align - 1UL);
end = ((end + 1UL) & ~(align - 1UL)) - 1UL;
if (start < end)
load_segment = start;
}
}
}
return (load_segment);
}
uint8_t
kboot_get_kernel_machine_bits(void)
{
static uint8_t bits = 0;
struct old_utsname utsname;
int ret;
if (bits == 0) {
/* Default is 32-bit kernel */
bits = 32;
/* Try to get system type */
memset(&utsname, 0, sizeof(utsname));
ret = host_uname(&utsname);
if (ret == 0) {
if (strcmp(utsname.machine, "ppc64") == 0)
bits = 64;
else if (strcmp(utsname.machine, "ppc64le") == 0)
bits = 64;
}
}
return (bits);
}
int
kboot_getdev(void **vdev, const char *devspec, const char **path)
{
int i, rv;
const char *devpath, *filepath;
struct devsw *dv;
struct devdesc *desc;
if (devspec == NULL) {
rv = kboot_getdev(vdev, getenv("currdev"), NULL);
if (rv == 0 && path != NULL)
*path = devspec;
return (rv);
}
if (strchr(devspec, ':') != NULL) {
devpath = devspec;
filepath = strchr(devspec, ':') + 1;
} else {
devpath = getenv("currdev");
filepath = devspec;
}
for (i = 0; (dv = devsw[i]) != NULL; i++) {
if (strncmp(dv->dv_name, devpath, strlen(dv->dv_name)) == 0)
goto found;
}
return (ENOENT);
found:
if (path != NULL && filepath != NULL)
*path = filepath;
else if (path != NULL)
*path = strchr(devspec, ':') + 1;
if (vdev != NULL) {
desc = malloc(sizeof(*desc));
desc->d_dev = dv;
desc->d_unit = 0;
desc->d_opendata = strdup(devpath);
*vdev = desc;
}
return (0);
}
int
main(int argc, const char **argv)
{
void *heapbase;
const size_t heapsize = 15*1024*1024;
const char *bootdev;
/* Give us a sane world if we're running as init */
do_init();
/*
* Setup the heap 15MB should be plenty
*/
heapbase = host_getmem(heapsize);
setheap(heapbase, heapbase + heapsize);
/*
* Set up console.
*/
cons_probe();
/* Choose bootdev if provided */
if (argc > 1)
bootdev = argv[1];
else
bootdev = "";
printf("Boot device: %s\n", bootdev);
archsw.arch_getdev = kboot_getdev;
archsw.arch_copyin = kboot_copyin;
archsw.arch_copyout = kboot_copyout;
archsw.arch_readin = kboot_readin;
archsw.arch_autoload = kboot_autoload;
archsw.arch_loadaddr = kboot_loadaddr;
archsw.arch_kexec_kseg_get = kboot_kseg_get;
printf("\n%s", bootprog_info);
setenv("currdev", bootdev, 1);
setenv("loaddev", bootdev, 1);
setenv("LINES", "24", 1);
setenv("usefdt", "1", 1);
interact(); /* doesn't return */
return (0);
}
void
exit(int code)
{
host_exit(code);
__unreachable();
}
void
delay(int usecs)
{
struct host_timeval tvi, tv;
uint64_t ti, t;
host_gettimeofday(&tvi, NULL);
ti = tvi.tv_sec*1000000 + tvi.tv_usec;
do {
host_gettimeofday(&tv, NULL);
t = tv.tv_sec*1000000 + tv.tv_usec;
} while (t < ti + usecs);
}
time_t
getsecs(void)
{
struct host_timeval tv;
host_gettimeofday(&tv, NULL);
return (tv.tv_sec);
}
time_t
time(time_t *tloc)
{
time_t rv;
rv = getsecs();
if (tloc != NULL)
*tloc = rv;
return (rv);
}
struct host_kexec_segment loaded_segments[HOST_KEXEC_SEGMENT_MAX];
int nkexec_segments = 0;
static ssize_t
get_phys_buffer(vm_offset_t dest, const size_t len, void **buf)
{
int i = 0;
const size_t segsize = 8*1024*1024;
if (nkexec_segments == HOST_KEXEC_SEGMENT_MAX)
panic("Tried to load too many kexec segments");
for (i = 0; i < nkexec_segments; i++) {
if (dest >= (vm_offset_t)loaded_segments[i].mem &&
dest < (vm_offset_t)loaded_segments[i].mem +
loaded_segments[i].memsz)
goto out;
}
loaded_segments[nkexec_segments].buf = host_getmem(segsize);
loaded_segments[nkexec_segments].bufsz = segsize;
loaded_segments[nkexec_segments].mem = (void *)rounddown2(dest,segsize);
loaded_segments[nkexec_segments].memsz = segsize;
i = nkexec_segments;
nkexec_segments++;
out:
*buf = loaded_segments[i].buf + (dest -
(vm_offset_t)loaded_segments[i].mem);
return (min(len,loaded_segments[i].bufsz - (dest -
(vm_offset_t)loaded_segments[i].mem)));
}
ssize_t
kboot_copyin(const void *src, vm_offset_t dest, const size_t len)
{
ssize_t segsize, remainder;
void *destbuf;
remainder = len;
do {
segsize = get_phys_buffer(dest, remainder, &destbuf);
bcopy(src, destbuf, segsize);
remainder -= segsize;
src += segsize;
dest += segsize;
} while (remainder > 0);
return (len);
}
ssize_t
kboot_copyout(vm_offset_t src, void *dest, const size_t len)
{
ssize_t segsize, remainder;
void *srcbuf;
remainder = len;
do {
segsize = get_phys_buffer(src, remainder, &srcbuf);
bcopy(srcbuf, dest, segsize);
remainder -= segsize;
src += segsize;
dest += segsize;
} while (remainder > 0);
return (len);
}
ssize_t
kboot_readin(readin_handle_t fd, vm_offset_t dest, const size_t len)
{
void *buf;
size_t resid, chunk, get;
ssize_t got;
vm_offset_t p;
p = dest;
chunk = min(PAGE_SIZE, len);
buf = malloc(chunk);
if (buf == NULL) {
printf("kboot_readin: buf malloc failed\n");
return (0);
}
for (resid = len; resid > 0; resid -= got, p += got) {
get = min(chunk, resid);
got = VECTX_READ(fd, buf, get);
if (got <= 0) {
if (got < 0)
printf("kboot_readin: read failed\n");
break;
}
kboot_copyin(buf, p, got);
}
free (buf);
return (len - resid);
}
int
kboot_autoload(void)
{
return (0);
}
uint64_t
kboot_loadaddr(u_int type, void *data, uint64_t addr)
{
if (type == LOAD_ELF)
addr = roundup(addr, PAGE_SIZE);
else
addr += kboot_get_phys_load_segment();
return (addr);
}
static void
kboot_kseg_get(int *nseg, void **ptr)
{
#if 0
int a;
for (a = 0; a < nkexec_segments; a++) {
printf("kseg_get: %jx %jx %jx %jx\n",
(uintmax_t)loaded_segments[a].buf,
(uintmax_t)loaded_segments[a].bufsz,
(uintmax_t)loaded_segments[a].mem,
(uintmax_t)loaded_segments[a].memsz);
}
#endif
*nseg = nkexec_segments;
*ptr = &loaded_segments[0];
}
/*
* Since proper fdt command handling function is defined in fdt_loader_cmd.c,
* and declaring it as extern is in contradiction with COMMAND_SET() macro
* (which uses static pointer), we're defining wrapper function, which
* calls the proper fdt handling routine.
*/
static int
command_fdt(int argc, char *argv[])
{
return (command_fdt_internal(argc, argv));
}
COMMAND_SET(fdt, "fdt", "flattened device tree handling", command_fdt);