* Copyright (c) 2015-2017 Jared McNeill <jmcneill@invisible.ca>

/* $NetBSD: fdt_boot.c,v 1.7 2024/12/20 07:55:45 mlelstv Exp $ */

/*-
* Copyright (c) 2015-2017 Jared McNeill <[email protected]>
* 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 THE AUTHOR 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.
*/

/*-
* Copyright (c) 2022 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nick Hudson
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__KERNEL_RCSID(0, "$NetBSD: fdt_boot.c,v 1.7 2024/12/20 07:55:45 mlelstv Exp $");

#include "opt_efi.h"
#include "opt_md.h"

#include <sys/param.h>

#include <sys/bootblock.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/fcntl.h>
#include <sys/md5.h>
#include <sys/optstr.h>
#include <sys/rnd.h>
#include <sys/rndsource.h>
#include <sys/uuid.h>
#include <sys/vnode.h>

#include <net/if.h>
#include <net/if_dl.h>

#include <uvm/uvm_extern.h>

#include <libfdt.h>

#include <dev/fdt/fdtvar.h>
#include <dev/fdt/fdt_boot.h>
#include <dev/fdt/fdt_memory.h>

#ifndef FDT_MAX_BOOT_STRING
#define FDT_MAX_BOOT_STRING 1024
#endif
static char bootargs[FDT_MAX_BOOT_STRING] = "";

#ifdef EFI_RUNTIME
#include <machine/efirt.h>

void fdt_map_efi_runtime(const char *, enum cpu_efirt_mem_type);

#endif

#ifdef MEMORY_DISK_DYNAMIC
#include <dev/md.h>

static uint64_t initrd_start, initrd_end;
#endif

static uint64_t rndseed_start, rndseed_end; /* our on-disk seed */
static uint64_t efirng_start, efirng_end; /* firmware's EFI RNG output */
static struct krndsource efirng_source;

static void
fdt_probe_range(const char *startname, const char *endname,
uint64_t *pstart, uint64_t *pend)
{
int chosen, len;
const void *start_data, *end_data;

*pstart = *pend = 0;

chosen = OF_finddevice("/chosen");
if (chosen < 0)
return;

start_data = fdtbus_get_prop(chosen, startname, &len);
end_data = fdtbus_get_prop(chosen, endname, NULL);
if (start_data == NULL || end_data == NULL)
return;

switch (len) {
case 4:
*pstart = be32dec(start_data);
*pend = be32dec(end_data);
break;
case 8:
*pstart = be64dec(start_data);
*pend = be64dec(end_data);
break;
default:
printf("Unsupported len %d for /chosen `%s'\n",
len, startname);
return;
}
}

static void *
fdt_map_range(uint64_t start, uint64_t end, uint64_t *psize,
const char *purpose)
{
const paddr_t startpa = trunc_page(start);
const paddr_t endpa = round_page(end);
paddr_t pa;
vaddr_t va;
void *ptr;

*psize = end - start;
if (*psize == 0)
return NULL;

const vaddr_t voff = start & PAGE_MASK;

// XXX NH add an align so map_chunk works betterer?
va = uvm_km_alloc(kernel_map, endpa - startpa, 0,
UVM_KMF_VAONLY | UVM_KMF_NOWAIT);
if (va == 0) {
printf("Failed to allocate VA for %s\n", purpose);
return NULL;
}
ptr = (void *)(va + voff);

// XXX NH map chunk
for (pa = startpa; pa < endpa; pa += PAGE_SIZE, va += PAGE_SIZE)
pmap_kenter_pa(va, pa, VM_PROT_READ | VM_PROT_WRITE, 0);
pmap_update(pmap_kernel());

return ptr;
}

static void
fdt_unmap_range(void *ptr, uint64_t size)
{
const char *start = ptr, *end = start + size;
const vaddr_t startva = trunc_page((vaddr_t)(uintptr_t)start);
const vaddr_t endva = round_page((vaddr_t)(uintptr_t)end);
const vsize_t sz = endva - startva;

pmap_kremove(startva, sz);
pmap_update(pmap_kernel());

uvm_km_free(kernel_map, startva, sz, UVM_KMF_VAONLY);
}

char *
fdt_get_bootargs(void)
{
const int chosen = OF_finddevice("/chosen");

if (chosen >= 0)
OF_getprop(chosen, "bootargs", bootargs, sizeof(bootargs));
return bootargs;
}

void
fdt_probe_initrd(void)
{

#ifdef MEMORY_DISK_DYNAMIC
fdt_probe_range("linux,initrd-start", "linux,initrd-end",
&initrd_start, &initrd_end);
#endif
}

void
fdt_setup_initrd(void)
{
#ifdef MEMORY_DISK_DYNAMIC
void *md_start;
uint64_t initrd_size;

md_start = fdt_map_range(initrd_start, initrd_end, &initrd_size,
"initrd");
if (md_start == NULL)
return;
md_root_setconf(md_start, initrd_size);
#endif
}

void
fdt_reserve_initrd(void)
{
#ifdef MEMORY_DISK_DYNAMIC
const uint64_t initrd_size =
round_page(initrd_end) - trunc_page(initrd_start);

if (initrd_size > 0)
fdt_memory_remove_range(trunc_page(initrd_start), initrd_size);
#endif
}

void
fdt_probe_rndseed(void)
{

fdt_probe_range("netbsd,rndseed-start", "netbsd,rndseed-end",
&rndseed_start, &rndseed_end);
}

void
fdt_setup_rndseed(void)
{
uint64_t rndseed_size;
void *rndseed;

rndseed = fdt_map_range(rndseed_start, rndseed_end, &rndseed_size,
"rndseed");
if (rndseed == NULL)
return;
rnd_seed(rndseed, rndseed_size);
fdt_unmap_range(rndseed, rndseed_size);
}

void
fdt_reserve_rndseed(void)
{
const uint64_t rndseed_size =
round_page(rndseed_end) - trunc_page(rndseed_start);

if (rndseed_size > 0)
fdt_memory_remove_range(trunc_page(rndseed_start),
rndseed_size);
}

void
fdt_probe_efirng(void)
{

fdt_probe_range("netbsd,efirng-start", "netbsd,efirng-end",
&efirng_start, &efirng_end);
}

void
fdt_setup_efirng(void)
{
uint64_t efirng_size;
void *efirng;

efirng = fdt_map_range(efirng_start, efirng_end, &efirng_size,
"efirng");
if (efirng == NULL)
return;

rnd_attach_source(&efirng_source, "efirng", RND_TYPE_RNG,
RND_FLAG_DEFAULT);

/*
* We don't really have specific information about the physical
* process underlying the data provided by the firmware via the
* EFI RNG API, so the entropy estimate here is heuristic.
* What efiboot provides us is up to 4096 bytes of data from
* the EFI RNG API, although in principle it may return short.
*
* The UEFI Specification (2.8 Errata A, February 2020[1]) says
*
* When a Deterministic Random Bit Generator (DRBG) is
* used on the output of a (raw) entropy source, its
* security level must be at least 256 bits.
*
* It's not entirely clear whether `it' refers to the DRBG or
* the entropy source; if it refers to the DRBG, it's not
* entirely clear how ANSI X9.31 3DES, one of the options for
* DRBG in the UEFI spec, can provide a `256-bit security
* level' because it has only 232 bits of inputs (three 56-bit
* keys and one 64-bit block). That said, even if it provides
* only 232 bits of entropy, that's enough to prevent all
* attacks and we probably get a few more bits from sampling
* the clock anyway.
*
* In the event we get raw samples, e.g. the bits sampled by a
* ring oscillator, we hope that the samples have at least half
* a bit of entropy per bit of data -- and efiboot tries to
* draw 4096 bytes to provide plenty of slop. Hence we divide
* the total number of bits by two and clamp at 256. There are
* ways this could go wrong, but on most machines it should
* behave reasonably.
*
* [1] https://uefi.org/sites/default/files/resources/UEFI_Spec_2_8_A_Feb14.pdf
*/
rnd_add_data(&efirng_source, efirng, efirng_size,
MIN(256, efirng_size*NBBY/2));

explicit_memset(efirng, 0, efirng_size);
fdt_unmap_range(efirng, efirng_size);
}

void
fdt_reserve_efirng(void)
{
const uint64_t efirng_size =
round_page(efirng_end) - trunc_page(efirng_start);

if (efirng_size > 0)
fdt_memory_remove_range(trunc_page(efirng_start), efirng_size);
}

#ifdef EFI_RUNTIME
void
fdt_map_efi_runtime(const char *prop, enum cpu_efirt_mem_type type)
{
int len;

const int chosen_off = fdt_path_offset(fdtbus_get_data(), "/chosen");
if (chosen_off < 0)
return;

const uint64_t *map = fdt_getprop(fdtbus_get_data(), chosen_off, prop, &len);
if (map == NULL)
return;

while (len >= 24) {
const paddr_t pa = be64toh(map[0]);
const vaddr_t va = be64toh(map[1]);
const size_t sz = be64toh(map[2]);
#if 0
VPRINTF("%s: %s %#" PRIxPADDR "-%#" PRIxVADDR " (%#" PRIxVADDR
"-%#" PRIxVSIZE ")\n", __func__, prop, pa, pa + sz - 1,
va, va + sz - 1);
#endif
cpu_efirt_map_range(va, pa, sz, type);
map += 3;
len -= 24;
}
}
#endif

void
fdt_update_stdout_path(void *fdt, const char *boot_args)
{
const char *stdout_path;
char buf[256];

const int chosen_off = fdt_path_offset(fdt, "/chosen");
if (chosen_off == -1)
return;

if (optstr_get_string(boot_args, "stdout-path", &stdout_path) == false)
return;

const char *ep = strchr(stdout_path, ' ');
size_t stdout_path_len = ep ? (ep - stdout_path) : strlen(stdout_path);
if (stdout_path_len >= sizeof(buf))
return;

strncpy(buf, stdout_path, stdout_path_len);
buf[stdout_path_len] = '\0';
fdt_setprop(fdt, chosen_off, "stdout-path",
buf, stdout_path_len + 1);
}

static void
fdt_detect_root_device(device_t dev)
{
int error, len;

const int chosen = OF_finddevice("/chosen");
if (chosen < 0)
return;

if (of_hasprop(chosen, "netbsd,mbr") &&
of_hasprop(chosen, "netbsd,partition")) {
struct mbr_sector mbr;
uint8_t buf[DEV_BSIZE];
uint8_t hash[16];
const uint8_t *rhash;
struct vnode *vp;
MD5_CTX md5ctx;
size_t resid;
u_int part;

/*
* The bootloader has passed in a partition index and MD5 hash
* of the MBR sector. Read the MBR of this device, calculate the
* hash, and compare it with the value passed in.
*/
rhash = fdtbus_get_prop(chosen, "netbsd,mbr", &len);
if (rhash == NULL || len != 16)
return;
of_getprop_uint32(chosen, "netbsd,partition", &part);
if (part >= MAXPARTITIONS)
return;

vp = opendisk(dev);
if (!vp)
return;
error = vn_rdwr(UIO_READ, vp, buf, sizeof(buf), 0, UIO_SYSSPACE,
IO_NODELOCKED, NOCRED, &resid, NULL);
VOP_CLOSE(vp, FREAD, NOCRED);
vput(vp);

if (error != 0)
return;

memcpy(&mbr, buf, sizeof(mbr));
MD5Init(&md5ctx);
MD5Update(&md5ctx, (void *)&mbr, sizeof(mbr));
MD5Final(hash, &md5ctx);

if (memcmp(rhash, hash, 16) == 0) {
booted_device = dev;
booted_partition = part;
}

return;
}

if (of_hasprop(chosen, "netbsd,gpt-guid")) {
const struct uuid *guid =
fdtbus_get_prop(chosen, "netbsd,gpt-guid", &len);

if (guid == NULL || len != 16)
return;

char guidstr[UUID_STR_LEN];
uuid_snprintf(guidstr, sizeof(guidstr), guid);

device_t dv = dkwedge_find_by_wname(guidstr);
if (dv != NULL)
booted_device = dv;

return;
}

if (of_hasprop(chosen, "netbsd,gpt-label")) {
const char *label = fdtbus_get_string(chosen, "netbsd,gpt-label");
if (label == NULL || *label == '\0')
return;

device_t dv = dkwedge_find_by_wname(label);
if (dv != NULL)
booted_device = dv;

return;
}

if (of_hasprop(chosen, "netbsd,booted-mac-address")) {
const uint8_t *macaddr =
fdtbus_get_prop(chosen, "netbsd,booted-mac-address", &len);
struct ifnet *ifp;

if (macaddr == NULL || len != 6)
return;

int s = pserialize_read_enter();
IFNET_READER_FOREACH(ifp) {
if (memcmp(macaddr, CLLADDR(ifp->if_sadl), len) == 0) {
device_t dv = device_find_by_xname(ifp->if_xname);
if (dv != NULL)
booted_device = dv;
break;
}
}
pserialize_read_exit(s);

return;
}
}

void
fdt_cpu_rootconf(void)
{
device_t dev;
deviter_t di;

if (booted_device != NULL)
return;

for (dev = deviter_first(&di, 0); dev; dev = deviter_next(&di)) {
if (device_class(dev) != DV_DISK)
continue;

fdt_detect_root_device(dev);

if (booted_device != NULL)
break;
}
deviter_release(&di);
}