blob: 1776fb1838c6c81e27ace2d452469830620eec03 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Bootmethod for ChromiumOS
*
* Copyright 2023 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#define LOG_CATEGORY UCLASS_BOOTSTD
#include <common.h>
#include <blk.h>
#include <bootdev.h>
#include <bootflow.h>
#include <bootm.h>
#include <bootmeth.h>
#include <display_options.h>
#include <dm.h>
#include <malloc.h>
#include <mapmem.h>
#include <part.h>
#include <linux/sizes.h>
#include "bootmeth_cros.h"
/*
* Layout of the ChromeOS kernel
*
* Partitions 2 and 4 contain kernels
*
* Contents are:
*
* Offset Contents
* 0 struct vb2_keyblock
* m struct vb2_kernel_preamble
* m + n kernel buffer
*
* m is keyblock->keyblock_size
* n is preamble->preamble_size
*
* The kernel buffer itself consists of various parts:
*
* Offset Contents
* m + n kernel image (Flat vmlinux binary or FIT)
* b - 8KB Command line text
* b - 4KB X86 setup block (struct boot_params, extends for about 16KB)
* b X86 bootloader (continuation of setup block)
* b + 16KB X86 setup block (copy, used for hold data pointed to)
*
* b is m + n + preamble->bootloader_address - preamble->body_load_address
*
* Useful metadata extends from b - 8KB through to b + 32 KB
*/
enum {
PROBE_SIZE = SZ_4K, /* initial bytes read from partition */
X86_SETUP_OFFSET = -0x1000, /* setup offset relative to base */
CMDLINE_OFFSET = -0x2000, /* cmdline offset relative to base */
X86_KERNEL_OFFSET = 0x4000, /* kernel offset relative to base */
};
/**
* struct cros_priv - Private data
*
* This is read from the disk and recorded for use when the full kernel must
* be loaded and booted
*
* @body_offset: Offset of kernel body from start of partition (in bytes)
* @body_size: Size of kernel body in bytes
* @part_start: Block offset of selected partition from the start of the disk
* @body_load_address: Nominal load address for kernel body
* @bootloader_address: Address of bootloader, after body is loaded at
* body_load_address
* @bootloader_size: Size of bootloader in bytes
* @info_buf: Buffer containing ChromiumOS info
*/
struct cros_priv {
ulong body_offset;
ulong body_size;
lbaint_t part_start;
ulong body_load_address;
ulong bootloader_address;
ulong bootloader_size;
void *info_buf;
};
static int cros_check(struct udevice *dev, struct bootflow_iter *iter)
{
/* This only works on block and network devices */
if (bootflow_iter_check_blk(iter))
return log_msg_ret("blk", -ENOTSUPP);
return 0;
}
static int copy_cmdline(const char *from, const char *uuid, char **bufp)
{
const int maxlen = 2048;
char buf[maxlen];
char *cmd, *to, *end;
int len;
/* Allow space for cmdline + UUID */
len = strnlen(from, sizeof(buf));
if (len >= maxlen)
return -E2BIG;
log_debug("uuid %d %s\n", uuid ? (int)strlen(uuid) : 0, uuid);
for (to = buf, end = buf + maxlen - UUID_STR_LEN - 1; *from; from++) {
if (to >= end)
return -E2BIG;
if (from[0] == '%' && from[1] == 'U' && uuid &&
strlen(uuid) == UUID_STR_LEN) {
strcpy(to, uuid);
to += UUID_STR_LEN;
from++;
} else {
*to++ = *from;
}
}
*to = '\0';
len = to - buf;
cmd = strdup(buf);
if (!cmd)
return -ENOMEM;
free(*bufp);
*bufp = cmd;
return 0;
}
/**
* scan_part() - Scan a kernel partition to see if has a ChromeOS header
*
* This reads the first PROBE_SIZE of a partition, loookng for
* VB2_KEYBLOCK_MAGIC
*
* @blk: Block device to scan
* @partnum: Partition number to scan
* @info: Please to put partition info
* @hdrp: Return allocated keyblock header on success
*/
static int scan_part(struct udevice *blk, int partnum,
struct disk_partition *info, struct vb2_keyblock **hdrp)
{
struct blk_desc *desc = dev_get_uclass_plat(blk);
struct vb2_keyblock *hdr;
ulong num_blks;
int ret;
ret = part_get_info(desc, partnum, info);
if (ret)
return log_msg_ret("part", ret);
/* Make a buffer for the header information */
num_blks = PROBE_SIZE >> desc->log2blksz;
log_debug("Reading header, blk=%s, start=%lx, blocks=%lx\n",
blk->name, (ulong)info->start, num_blks);
hdr = memalign(SZ_1K, PROBE_SIZE);
if (!hdr)
return log_msg_ret("hdr", -ENOMEM);
ret = blk_read(blk, info->start, num_blks, hdr);
if (ret != num_blks) {
free(hdr);
return log_msg_ret("inf", -EIO);
}
if (memcmp(VB2_KEYBLOCK_MAGIC, hdr->magic, VB2_KEYBLOCK_MAGIC_SIZE)) {
free(hdr);
return -ENOENT;
}
*hdrp = hdr;
return 0;
}
/**
* cros_read_buf() - Read information into a buf and parse it
*
* @bflow: Bootflow to update
* @buf: Buffer to use
* @size: Size of buffer and number of bytes to read thereinto
* @start: Start offset to read from on disk
* @before_base: Number of bytes to read before the bootloader base
* @uuid: UUID string if supported, else NULL
* Return: 0 if OK, -ENOMEM if out of memory, -EIO on read failure
*/
static int cros_read_buf(struct bootflow *bflow, void *buf, ulong size,
loff_t start, ulong before_base, const char *uuid)
{
struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
ulong base, setup, cmdline, kern_base;
ulong num_blks;
int ret;
num_blks = size >> desc->log2blksz;
log_debug("Reading info to %lx, blk=%s, size=%lx, blocks=%lx\n",
(ulong)map_to_sysmem(buf), bflow->blk->name, size, num_blks);
ret = blk_read(bflow->blk, start, num_blks, buf);
if (ret != num_blks)
return log_msg_ret("inf", -EIO);
base = map_to_sysmem(buf) + before_base;
setup = base + X86_SETUP_OFFSET;
cmdline = base + CMDLINE_OFFSET;
kern_base = base + X86_KERNEL_OFFSET;
log_debug("base %lx setup %lx cmdline %lx kern_base %lx\n", base,
setup, cmdline, kern_base);
#ifdef CONFIG_X86
const char *version;
version = zimage_get_kernel_version(map_sysmem(setup, 0),
map_sysmem(kern_base, 0));
log_debug("version %s\n", version);
if (version)
bflow->name = strdup(version);
#endif
if (!bflow->name)
bflow->name = strdup("ChromeOS");
if (!bflow->name)
return log_msg_ret("nam", -ENOMEM);
bflow->os_name = strdup("ChromeOS");
if (!bflow->os_name)
return log_msg_ret("os", -ENOMEM);
ret = copy_cmdline(map_sysmem(cmdline, 0), uuid, &bflow->cmdline);
if (ret)
return log_msg_ret("cmd", ret);
bflow->x86_setup = map_sysmem(setup, 0);
return 0;
}
/**
* cros_read_info() - Read information and fill out the bootflow
*
* @bflow: Bootflow to update
* @uuid: UUID string if supported, else NULL
* @preamble: Kernel preamble information
* Return: 0 if OK, -ENOMEM if out of memory, -EIO on read failure
*/
static int cros_read_info(struct bootflow *bflow, const char *uuid,
const struct vb2_kernel_preamble *preamble)
{
struct cros_priv *priv = bflow->bootmeth_priv;
struct udevice *blk = bflow->blk;
struct blk_desc *desc = dev_get_uclass_plat(blk);
ulong offset, size, before_base;
void *buf;
int ret;
log_debug("Kernel preamble at %lx, version major %x, minor %x\n",
(ulong)map_to_sysmem(preamble),
preamble->header_version_major,
preamble->header_version_minor);
log_debug(" - load_address %lx, bl_addr %lx, bl_size %lx\n",
(ulong)preamble->body_load_address,
(ulong)preamble->bootloader_address,
(ulong)preamble->bootloader_size);
priv->body_size = preamble->body_signature.data_size;
priv->body_load_address = preamble->body_load_address;
priv->bootloader_address = preamble->bootloader_address;
priv->bootloader_size = preamble->bootloader_size;
log_debug("Kernel body at %lx size %lx\n", priv->body_offset,
priv->body_size);
/* Work out how many bytes to read before the bootloader base */
before_base = -CMDLINE_OFFSET;
/* Read the cmdline through to the end of the bootloader */
size = priv->bootloader_size + before_base;
offset = priv->body_offset +
(priv->bootloader_address - priv->body_load_address) +
CMDLINE_OFFSET;
buf = malloc(size);
if (!buf)
return log_msg_ret("buf", -ENOMEM);
ret = cros_read_buf(bflow, buf, size,
priv->part_start + (offset >> desc->log2blksz),
before_base, uuid);
if (ret) {
/* Clear this since the buffer is invalid */
bflow->x86_setup = NULL;
free(buf);
return log_msg_ret("pro", ret);
}
priv->info_buf = buf;
return 0;
}
static int cros_read_kernel(struct bootflow *bflow)
{
struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
struct cros_priv *priv = bflow->bootmeth_priv;
ulong base, setup;
ulong num_blks;
void *buf;
int ret;
bflow->size = priv->body_size;
buf = memalign(SZ_1K, priv->body_size);
if (!buf)
return log_msg_ret("buf", -ENOMEM);
/* Check that the header is not smaller than permitted */
if (priv->body_offset < PROBE_SIZE)
return log_msg_ret("san", EFAULT);
/* Read kernel body */
num_blks = priv->body_size >> desc->log2blksz;
log_debug("Reading body to %lx, blk=%s, size=%lx, blocks=%lx\n",
(ulong)map_to_sysmem(buf), bflow->blk->name, priv->body_size,
num_blks);
ret = blk_read(bflow->blk,
priv->part_start + (priv->body_offset >> desc->log2blksz),
num_blks, buf);
if (ret != num_blks)
return log_msg_ret("inf", -EIO);
base = map_to_sysmem(buf) + priv->bootloader_address -
priv->body_load_address;
setup = base + X86_SETUP_OFFSET;
bflow->buf = buf;
bflow->x86_setup = map_sysmem(setup, 0);
return 0;
}
static int cros_read_bootflow(struct udevice *dev, struct bootflow *bflow)
{
const struct vb2_kernel_preamble *preamble;
struct disk_partition info;
struct vb2_keyblock *hdr;
const char *uuid = NULL;
struct cros_priv *priv;
int part, ret;
log_debug("starting, part=%d\n", bflow->part);
/* We consider the whole disk, not any one partition */
if (bflow->part)
return log_msg_ret("max", -ENOENT);
/* Check partition 2 then 4 */
part = 2;
ret = scan_part(bflow->blk, part, &info, &hdr);
if (ret) {
part = 4;
ret = scan_part(bflow->blk, part, &info, &hdr);
if (ret)
return log_msg_ret("scan", ret);
}
bflow->part = part;
priv = malloc(sizeof(struct cros_priv));
if (!priv) {
free(hdr);
return log_msg_ret("buf", -ENOMEM);
}
bflow->bootmeth_priv = priv;
log_info("Selected partition %d, header at %lx\n", bflow->part,
(ulong)map_to_sysmem(hdr));
/* Grab a few things from the preamble */
preamble = (void *)hdr + hdr->keyblock_size;
priv->body_offset = hdr->keyblock_size + preamble->preamble_size;
priv->part_start = info.start;
/* Now read everything we can learn about kernel */
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
uuid = info.uuid;
#endif
ret = cros_read_info(bflow, uuid, preamble);
preamble = NULL;
free(hdr);
if (ret)
return log_msg_ret("inf", ret);
bflow->size = priv->body_size;
bflow->state = BOOTFLOWST_READY;
return 0;
}
static int cros_read_file(struct udevice *dev, struct bootflow *bflow,
const char *file_path, ulong addr, ulong *sizep)
{
return -ENOSYS;
}
#if CONFIG_IS_ENABLED(BOOSTD_FULL)
static int cros_read_all(struct udevice *dev, struct bootflow *bflow)
{
int ret;
if (bflow->buf)
return log_msg_ret("ld", -EALREADY);
ret = cros_read_kernel(bflow);
if (ret)
return log_msg_ret("rd", ret);
return 0;
}
#endif /* BOOSTD_FULL */
static int cros_boot(struct udevice *dev, struct bootflow *bflow)
{
int ret;
if (!bflow->buf) {
ret = cros_read_kernel(bflow);
if (ret)
return log_msg_ret("rd", ret);
}
if (IS_ENABLED(CONFIG_X86)) {
ret = zboot_start(map_to_sysmem(bflow->buf), bflow->size, 0, 0,
map_to_sysmem(bflow->x86_setup),
bflow->cmdline);
} else {
ret = bootm_boot_start(map_to_sysmem(bflow->buf),
bflow->cmdline);
}
return log_msg_ret("go", ret);
}
static int cros_bootmeth_bind(struct udevice *dev)
{
struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
plat->desc = "ChromiumOS boot";
return 0;
}
static struct bootmeth_ops cros_bootmeth_ops = {
.check = cros_check,
.read_bootflow = cros_read_bootflow,
.read_file = cros_read_file,
.boot = cros_boot,
#if CONFIG_IS_ENABLED(BOOSTD_FULL)
.read_all = cros_read_all,
#endif /* BOOSTD_FULL */
};
static const struct udevice_id cros_bootmeth_ids[] = {
{ .compatible = "u-boot,cros" },
{ }
};
U_BOOT_DRIVER(bootmeth_cros) = {
.name = "bootmeth_cros",
.id = UCLASS_BOOTMETH,
.of_match = cros_bootmeth_ids,
.ops = &cros_bootmeth_ops,
.bind = cros_bootmeth_bind,
};