#include <linux/crc32.h>
#include <linux/etherdevice.h>
#include <linux/export.h>
#include <linux/hex.h>
#include <linux/if_ether.h>
#include <linux/nvmem-consumer.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/slab.h>
#include "u-boot-env.h"
struct u_boot_env_image_single {
__le32 crc32;
uint8_t data[];
} __packed;
struct u_boot_env_image_redundant {
__le32 crc32;
u8 mark;
uint8_t data[];
} __packed;
struct u_boot_env_image_broadcom {
__le32 magic;
__le32 len;
__le32 crc32;
DECLARE_FLEX_ARRAY(uint8_t, data);
} __packed;
static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index,
unsigned int offset, void *buf, size_t bytes)
{
u8 mac[ETH_ALEN];
if (bytes != MAC_ADDR_STR_LEN)
return -EINVAL;
if (!mac_pton(buf, mac))
return -EINVAL;
if (index)
eth_addr_add(mac, index);
ether_addr_copy(buf, mac);
return 0;
}
static int u_boot_env_parse_cells(struct device *dev, struct nvmem_device *nvmem, uint8_t *buf,
size_t data_offset, size_t data_len)
{
char *data = buf + data_offset;
char *var, *value, *eq;
for (var = data;
var < data + data_len && *var;
var = value + strlen(value) + 1) {
struct nvmem_cell_info info = {};
eq = strchr(var, '=');
if (!eq)
break;
*eq = '\0';
value = eq + 1;
info.name = devm_kstrdup(dev, var, GFP_KERNEL);
if (!info.name)
return -ENOMEM;
info.offset = data_offset + value - data;
info.bytes = strlen(value);
info.np = of_get_child_by_name(dev->of_node, info.name);
if (!strcmp(var, "ethaddr")) {
info.raw_len = strlen(value);
info.bytes = ETH_ALEN;
info.read_post_process = u_boot_env_read_post_process_ethaddr;
}
nvmem_add_one_cell(nvmem, &info);
}
return 0;
}
int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem,
enum u_boot_env_format format)
{
size_t crc32_data_offset;
size_t crc32_data_len;
size_t crc32_offset;
uint32_t *crc32_addr;
size_t data_offset;
size_t data_len;
size_t dev_size;
uint32_t crc32;
uint32_t calc;
uint8_t *buf;
u32 env_size;
int bytes;
int err;
dev_size = device_property_read_u32(dev, "env-size", &env_size) ?
nvmem_dev_size(nvmem) : (size_t)env_size;
buf = kzalloc(dev_size, GFP_KERNEL);
if (!buf) {
err = -ENOMEM;
goto err_out;
}
bytes = nvmem_device_read(nvmem, 0, dev_size, buf);
if (bytes < 0) {
err = bytes;
goto err_kfree;
} else if (bytes != dev_size) {
err = -EIO;
goto err_kfree;
}
switch (format) {
case U_BOOT_FORMAT_SINGLE:
crc32_offset = offsetof(struct u_boot_env_image_single, crc32);
crc32_data_offset = offsetof(struct u_boot_env_image_single, data);
data_offset = offsetof(struct u_boot_env_image_single, data);
break;
case U_BOOT_FORMAT_REDUNDANT:
crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32);
crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data);
data_offset = offsetof(struct u_boot_env_image_redundant, data);
break;
case U_BOOT_FORMAT_BROADCOM:
crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32);
crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data);
data_offset = offsetof(struct u_boot_env_image_broadcom, data);
break;
}
if (dev_size < data_offset) {
dev_err(dev, "Device too small for u-boot-env\n");
err = -EIO;
goto err_kfree;
}
crc32_addr = (uint32_t *)(buf + crc32_offset);
crc32 = *crc32_addr;
crc32_data_len = dev_size - crc32_data_offset;
data_len = dev_size - data_offset;
calc = crc32_le(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L;
if (calc != crc32) {
dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32);
err = -EINVAL;
goto err_kfree;
}
buf[dev_size - 1] = '\0';
err = u_boot_env_parse_cells(dev, nvmem, buf, data_offset, data_len);
err_kfree:
kfree(buf);
err_out:
return err;
}
EXPORT_SYMBOL_GPL(u_boot_env_parse);
static int u_boot_env_add_cells(struct nvmem_layout *layout)
{
struct device *dev = &layout->dev;
enum u_boot_env_format format;
format = (uintptr_t)device_get_match_data(dev);
return u_boot_env_parse(dev, layout->nvmem, format);
}
static int u_boot_env_probe(struct nvmem_layout *layout)
{
layout->add_cells = u_boot_env_add_cells;
return nvmem_layout_register(layout);
}
static void u_boot_env_remove(struct nvmem_layout *layout)
{
nvmem_layout_unregister(layout);
}
static const struct of_device_id u_boot_env_of_match_table[] = {
{ .compatible = "u-boot,env", .data = (void *)U_BOOT_FORMAT_SINGLE, },
{ .compatible = "u-boot,env-redundant-bool", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
{ .compatible = "u-boot,env-redundant-count", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
{ .compatible = "brcm,env", .data = (void *)U_BOOT_FORMAT_BROADCOM, },
{},
};
static struct nvmem_layout_driver u_boot_env_layout = {
.driver = {
.name = "u-boot-env-layout",
.of_match_table = u_boot_env_of_match_table,
},
.probe = u_boot_env_probe,
.remove = u_boot_env_remove,
};
module_nvmem_layout_driver(u_boot_env_layout);
MODULE_AUTHOR("Rafał Miłecki");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table);
MODULE_DESCRIPTION("NVMEM layout driver for U-Boot environment variables");
