u-boot/boot/vbe_simple.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Verified Boot for Embedded (VBE) 'simple' method
*
* Copyright 2022 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*/
#define LOG_CATEGORY LOGC_BOOT
#include <common.h>
#include <bootdev.h>
#include <bootflow.h>
#include <bootmeth.h>
#include <dm.h>
#include <log.h>
#include <memalign.h>
#include <mmc.h>
#include <vbe.h>
#include <dm/device-internal.h>
#include <dm/ofnode.h>
#include <u-boot/crc.h>
#include "vbe_simple.h"
/** struct simple_nvdata - storage format for non-volatile data */
struct simple_nvdata {
u8 crc8;
u8 hdr;
u16 spare1;
u32 fw_vernum;
u8 spare2[0x38];
};
static int simple_read_version(struct udevice *dev, struct blk_desc *desc,
u8 *buf, struct simple_state *state)
{
struct simple_priv *priv = dev_get_priv(dev);
int start;
if (priv->version_size > MMC_MAX_BLOCK_LEN)
return log_msg_ret("ver", -E2BIG);
start = priv->area_start + priv->version_offset;
if (start & (MMC_MAX_BLOCK_LEN - 1))
return log_msg_ret("get", -EBADF);
start /= MMC_MAX_BLOCK_LEN;
if (blk_dread(desc, start, 1, buf) != 1)
return log_msg_ret("read", -EIO);
strlcpy(state->fw_version, buf, MAX_VERSION_LEN);
log_debug("version=%s\n", state->fw_version);
return 0;
}
static int simple_read_nvdata(struct udevice *dev, struct blk_desc *desc,
u8 *buf, struct simple_state *state)
{
struct simple_priv *priv = dev_get_priv(dev);
uint hdr_ver, hdr_size, size, crc;
const struct simple_nvdata *nvd;
int start;
if (priv->state_size > MMC_MAX_BLOCK_LEN)
return log_msg_ret("state", -E2BIG);
start = priv->area_start + priv->state_offset;
if (start & (MMC_MAX_BLOCK_LEN - 1))
return log_msg_ret("get", -EBADF);
start /= MMC_MAX_BLOCK_LEN;
if (blk_dread(desc, start, 1, buf) != 1)
return log_msg_ret("read", -EIO);
nvd = (struct simple_nvdata *)buf;
hdr_ver = (nvd->hdr & NVD_HDR_VER_MASK) >> NVD_HDR_VER_SHIFT;
hdr_size = (nvd->hdr & NVD_HDR_SIZE_MASK) >> NVD_HDR_SIZE_SHIFT;
if (hdr_ver != NVD_HDR_VER_CUR)
return log_msg_ret("hdr", -EPERM);
size = 1 << hdr_size;
if (size > sizeof(*nvd))
return log_msg_ret("sz", -ENOEXEC);
crc = crc8(0, buf + 1, size - 1);
if (crc != nvd->crc8)
return log_msg_ret("crc", -EPERM);
state->fw_vernum = nvd->fw_vernum;
log_debug("version=%s\n", state->fw_version);
return 0;
}
int vbe_simple_read_state(struct udevice *dev, struct simple_state *state)
{
ALLOC_CACHE_ALIGN_BUFFER(u8, buf, MMC_MAX_BLOCK_LEN);
struct simple_priv *priv = dev_get_priv(dev);
struct blk_desc *desc;
char devname[16];
const char *end;
int devnum;
int ret;
/* First figure out the block device */
log_debug("storage=%s\n", priv->storage);
devnum = trailing_strtoln_end(priv->storage, NULL, &end);
if (devnum == -1)
return log_msg_ret("num", -ENODEV);
if (end - priv->storage >= sizeof(devname))
return log_msg_ret("end", -E2BIG);
strlcpy(devname, priv->storage, end - priv->storage + 1);
log_debug("dev=%s, %x\n", devname, devnum);
desc = blk_get_dev(devname, devnum);
if (!desc)
return log_msg_ret("get", -ENXIO);
ret = simple_read_version(dev, desc, buf, state);
if (ret)
return log_msg_ret("ver", ret);
ret = simple_read_nvdata(dev, desc, buf, state);
if (ret)
return log_msg_ret("nvd", ret);
return 0;
}
static int vbe_simple_get_state_desc(struct udevice *dev, char *buf,
int maxsize)
{
struct simple_state state;
int ret;
ret = vbe_simple_read_state(dev, &state);
if (ret)
return log_msg_ret("read", ret);
if (maxsize < 30)
return -ENOSPC;
snprintf(buf, maxsize, "Version: %s\nVernum: %x/%x", state.fw_version,
state.fw_vernum >> FWVER_KEY_SHIFT,
state.fw_vernum & FWVER_FW_MASK);
return 0;
}
static int vbe_simple_read_bootflow(struct udevice *dev, struct bootflow *bflow)
{
int ret;
if (CONFIG_IS_ENABLED(BOOTMETH_VBE_SIMPLE_FW)) {
if (vbe_phase() == VBE_PHASE_FIRMWARE) {
ret = vbe_simple_read_bootflow_fw(dev, bflow);
if (ret)
return log_msg_ret("fw", ret);
return 0;
}
}
return -EINVAL;
}
static int vbe_simple_read_file(struct udevice *dev, struct bootflow *bflow,
const char *file_path, ulong addr, ulong *sizep)
{
int ret;
if (vbe_phase() == VBE_PHASE_OS) {
ret = bootmeth_common_read_file(dev, bflow, file_path, addr,
sizep);
if (ret)
return log_msg_ret("os", ret);
}
/* To be implemented */
return -EINVAL;
}
static struct bootmeth_ops bootmeth_vbe_simple_ops = {
.get_state_desc = vbe_simple_get_state_desc,
.read_bootflow = vbe_simple_read_bootflow,
.read_file = vbe_simple_read_file,
};
static int bootmeth_vbe_simple_probe(struct udevice *dev)
{
struct simple_priv *priv = dev_get_priv(dev);
memset(priv, '\0', sizeof(*priv));
if (dev_read_u32(dev, "area-start", &priv->area_start) ||
dev_read_u32(dev, "area-size", &priv->area_size) ||
dev_read_u32(dev, "version-offset", &priv->version_offset) ||
dev_read_u32(dev, "version-size", &priv->version_size) ||
dev_read_u32(dev, "state-offset", &priv->state_offset) ||
dev_read_u32(dev, "state-size", &priv->state_size))
return log_msg_ret("read", -EINVAL);
dev_read_u32(dev, "skip-offset", &priv->skip_offset);
priv->storage = strdup(dev_read_string(dev, "storage"));
if (!priv->storage)
return log_msg_ret("str", -EINVAL);
return 0;
}
static int bootmeth_vbe_simple_bind(struct udevice *dev)
{
struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
"VBE simple" : "vbe-simple";
plat->flags = BOOTMETHF_GLOBAL;
return 0;
}
#if CONFIG_IS_ENABLED(OF_REAL)
static const struct udevice_id generic_simple_vbe_simple_ids[] = {
{ .compatible = "fwupd,vbe-simple" },
{ }
};
#endif
U_BOOT_DRIVER(vbe_simple) = {
.name = "vbe_simple",
.id = UCLASS_BOOTMETH,
.of_match = of_match_ptr(generic_simple_vbe_simple_ids),
.ops = &bootmeth_vbe_simple_ops,
.bind = bootmeth_vbe_simple_bind,
.probe = bootmeth_vbe_simple_probe,
.flags = DM_FLAG_PRE_RELOC,
.priv_auto = sizeof(struct simple_priv),
};