blob: bd2dc34da7890523b0af52deb0f64c78dea9447d [file] [log] [blame]
/*
* RAM Oops/Panic logger
*
* Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
* Copyright (C) 2011 Kees Cook <keescook@chromium.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/pstore.h>
#include <linux/time.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/compiler.h>
#include <linux/pstore_ram.h>
#include <linux/of.h>
#include <linux/of_address.h>
#define RAMOOPS_KERNMSG_HDR "===="
#define MIN_MEM_SIZE 4096UL
static ulong record_size = MIN_MEM_SIZE;
module_param(record_size, ulong, 0400);
MODULE_PARM_DESC(record_size,
"size of each dump done on oops/panic");
static ulong ramoops_console_size = MIN_MEM_SIZE;
module_param_named(console_size, ramoops_console_size, ulong, 0400);
MODULE_PARM_DESC(console_size, "size of kernel console log");
static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
MODULE_PARM_DESC(pmsg_size, "size of user space message log");
static unsigned long long mem_address;
module_param(mem_address, ullong, 0400);
MODULE_PARM_DESC(mem_address,
"start of reserved RAM used to store oops/panic logs");
static ulong mem_size;
module_param(mem_size, ulong, 0400);
MODULE_PARM_DESC(mem_size,
"size of reserved RAM used to store oops/panic logs");
static unsigned int mem_type;
module_param(mem_type, uint, 0600);
MODULE_PARM_DESC(mem_type,
"set to 1 to try to use unbuffered memory (default 0)");
static int dump_oops = 1;
module_param(dump_oops, int, 0600);
MODULE_PARM_DESC(dump_oops,
"set to 1 to dump oopses, 0 to only dump panics (default 1)");
static int ramoops_ecc;
module_param_named(ecc, ramoops_ecc, int, 0600);
MODULE_PARM_DESC(ramoops_ecc,
"if non-zero, the option enables ECC support and specifies "
"ECC buffer size in bytes (1 is a special value, means 16 "
"bytes ECC)");
struct ramoops_context {
struct persistent_ram_zone **przs;
struct persistent_ram_zone *cprz;
struct persistent_ram_zone *fprz;
struct persistent_ram_zone *mprz;
phys_addr_t phys_addr;
unsigned long size;
unsigned int memtype;
size_t record_size;
size_t console_size;
size_t ftrace_size;
size_t pmsg_size;
int dump_oops;
struct persistent_ram_ecc_info ecc_info;
unsigned int max_dump_cnt;
unsigned int dump_write_cnt;
/* _read_cnt need clear on ramoops_pstore_open */
unsigned int dump_read_cnt;
unsigned int console_read_cnt;
unsigned int ftrace_read_cnt;
unsigned int pmsg_read_cnt;
struct pstore_info pstore;
};
static struct platform_device *dummy;
static struct ramoops_platform_data *dummy_data;
static int ramoops_pstore_open(struct pstore_info *psi)
{
struct ramoops_context *cxt = psi->data;
cxt->dump_read_cnt = 0;
cxt->console_read_cnt = 0;
cxt->ftrace_read_cnt = 0;
cxt->pmsg_read_cnt = 0;
return 0;
}
static struct persistent_ram_zone *
ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
u64 *id,
enum pstore_type_id *typep, enum pstore_type_id type,
bool update)
{
struct persistent_ram_zone *prz;
int i = (*c)++;
if (i >= max)
return NULL;
prz = przs[i];
if (!prz)
return NULL;
/* Update old/shadowed buffer. */
if (update)
persistent_ram_save_old(prz);
if (!persistent_ram_old_size(prz))
return NULL;
*typep = type;
*id = i;
return prz;
}
static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
bool *compressed)
{
char data_type;
int header_length = 0;
if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
&time->tv_nsec, &data_type, &header_length) == 3) {
if (data_type == 'C')
*compressed = true;
else
*compressed = false;
} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
&time->tv_sec, &time->tv_nsec, &header_length) == 2) {
*compressed = false;
} else {
time->tv_sec = 0;
time->tv_nsec = 0;
*compressed = false;
}
return header_length;
}
static bool prz_ok(struct persistent_ram_zone *prz)
{
return !!prz && !!(persistent_ram_old_size(prz) +
persistent_ram_ecc_string(prz, NULL, 0));
}
static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
int *count, struct timespec *time,
char **buf, bool *compressed,
ssize_t *ecc_notice_size,
struct pstore_info *psi)
{
ssize_t size;
struct ramoops_context *cxt = psi->data;
struct persistent_ram_zone *prz = NULL;
int header_length = 0;
/* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
* PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
* valid time stamps, so it is initialized to zero.
*/
time->tv_sec = 0;
time->tv_nsec = 0;
*compressed = false;
/* Find the next valid persistent_ram_zone for DMESG */
while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
cxt->max_dump_cnt, id, type,
PSTORE_TYPE_DMESG, 1);
if (!prz_ok(prz))
continue;
header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
time, compressed);
/* Clear and skip this DMESG record if it has no valid header */
if (!header_length) {
persistent_ram_free_old(prz);
persistent_ram_zap(prz);
prz = NULL;
}
}
if (!prz_ok(prz))
prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
1, id, type, PSTORE_TYPE_CONSOLE, 0);
if (!prz_ok(prz))
prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
1, id, type, PSTORE_TYPE_FTRACE, 0);
if (!prz_ok(prz))
prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
1, id, type, PSTORE_TYPE_PMSG, 0);
if (!prz_ok(prz))
return 0;
size = persistent_ram_old_size(prz) - header_length;
/* ECC correction notice */
*ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
*buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
if (*buf == NULL)
return -ENOMEM;
memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
return size;
}
static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
bool compressed)
{
char *hdr;
struct timespec timestamp;
size_t len;
/* Report zeroed timestamp if called before timekeeping has resumed. */
if (__getnstimeofday(&timestamp)) {
timestamp.tv_sec = 0;
timestamp.tv_nsec = 0;
}
hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
(long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
compressed ? 'C' : 'D');
WARN_ON_ONCE(!hdr);
len = hdr ? strlen(hdr) : 0;
persistent_ram_write(prz, hdr, len);
kfree(hdr);
return len;
}
static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
enum kmsg_dump_reason reason,
u64 *id, unsigned int part,
const char *buf,
bool compressed, size_t size,
struct pstore_info *psi)
{
struct ramoops_context *cxt = psi->data;
struct persistent_ram_zone *prz;
size_t hlen;
if (type == PSTORE_TYPE_CONSOLE) {
if (!cxt->cprz)
return -ENOMEM;
persistent_ram_write(cxt->cprz, buf, size);
return 0;
} else if (type == PSTORE_TYPE_FTRACE) {
if (!cxt->fprz)
return -ENOMEM;
persistent_ram_write(cxt->fprz, buf, size);
return 0;
} else if (type == PSTORE_TYPE_PMSG) {
if (!cxt->mprz)
return -ENOMEM;
persistent_ram_write(cxt->mprz, buf, size);
return 0;
}
if (type != PSTORE_TYPE_DMESG)
return -EINVAL;
/* Out of the various dmesg dump types, ramoops is currently designed
* to only store crash logs, rather than storing general kernel logs.
*/
if (reason != KMSG_DUMP_OOPS &&
reason != KMSG_DUMP_PANIC)
return -EINVAL;
/* Skip Oopes when configured to do so. */
if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
return -EINVAL;
/* Explicitly only take the first part of any new crash.
* If our buffer is larger than kmsg_bytes, this can never happen,
* and if our buffer is smaller than kmsg_bytes, we don't want the
* report split across multiple records.
*/
if (part != 1)
return -ENOSPC;
if (!cxt->przs)
return -ENOSPC;
prz = cxt->przs[cxt->dump_write_cnt];
hlen = ramoops_write_kmsg_hdr(prz, compressed);
if (size + hlen > prz->buffer_size)
size = prz->buffer_size - hlen;
persistent_ram_write(prz, buf, size);
cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
return 0;
}
static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
enum kmsg_dump_reason reason,
u64 *id, unsigned int part,
const char __user *buf,
bool compressed, size_t size,
struct pstore_info *psi)
{
if (type == PSTORE_TYPE_PMSG) {
struct ramoops_context *cxt = psi->data;
if (!cxt->mprz)
return -ENOMEM;
return persistent_ram_write_user(cxt->mprz, buf, size);
}
return -EINVAL;
}
static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
struct timespec time, struct pstore_info *psi)
{
struct ramoops_context *cxt = psi->data;
struct persistent_ram_zone *prz;
switch (type) {
case PSTORE_TYPE_DMESG:
if (id >= cxt->max_dump_cnt)
return -EINVAL;
prz = cxt->przs[id];
break;
case PSTORE_TYPE_CONSOLE:
prz = cxt->cprz;
break;
case PSTORE_TYPE_FTRACE:
prz = cxt->fprz;
break;
case PSTORE_TYPE_PMSG:
prz = cxt->mprz;
break;
default:
return -EINVAL;
}
persistent_ram_free_old(prz);
persistent_ram_zap(prz);
return 0;
}
static struct ramoops_context oops_cxt = {
.pstore = {
.owner = THIS_MODULE,
.name = "ramoops",
.open = ramoops_pstore_open,
.read = ramoops_pstore_read,
.write_buf = ramoops_pstore_write_buf,
.write_buf_user = ramoops_pstore_write_buf_user,
.erase = ramoops_pstore_erase,
},
};
static void ramoops_free_przs(struct ramoops_context *cxt)
{
int i;
if (!cxt->przs)
return;
for (i = 0; i < cxt->max_dump_cnt; i++)
persistent_ram_free(cxt->przs[i]);
kfree(cxt->przs);
cxt->max_dump_cnt = 0;
}
static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
phys_addr_t *paddr, size_t dump_mem_sz)
{
int err = -ENOMEM;
int i;
if (!cxt->record_size)
return 0;
if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
dev_err(dev, "no room for dumps\n");
return -ENOMEM;
}
cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
if (!cxt->max_dump_cnt)
return -ENOMEM;
cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
GFP_KERNEL);
if (!cxt->przs) {
dev_err(dev, "failed to initialize a prz array for dumps\n");
goto fail_mem;
}
for (i = 0; i < cxt->max_dump_cnt; i++) {
cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
&cxt->ecc_info,
cxt->memtype);
if (IS_ERR(cxt->przs[i])) {
err = PTR_ERR(cxt->przs[i]);
dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
cxt->record_size, (unsigned long long)*paddr, err);
while (i > 0) {
i--;
persistent_ram_free(cxt->przs[i]);
}
goto fail_prz;
}
*paddr += cxt->record_size;
}
return 0;
fail_prz:
kfree(cxt->przs);
fail_mem:
cxt->max_dump_cnt = 0;
return err;
}
static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
struct persistent_ram_zone **prz,
phys_addr_t *paddr, size_t sz, u32 sig)
{
if (!sz)
return 0;
if (*paddr + sz - cxt->phys_addr > cxt->size) {
dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
sz, (unsigned long long)*paddr,
cxt->size, (unsigned long long)cxt->phys_addr);
return -ENOMEM;
}
*prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
if (IS_ERR(*prz)) {
int err = PTR_ERR(*prz);
dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
sz, (unsigned long long)*paddr, err);
return err;
}
persistent_ram_zap(*prz);
*paddr += sz;
return 0;
}
static int ramoops_parse_dt_size(struct platform_device *pdev,
const char *propname, u32 *value)
{
u32 val32 = 0;
int ret;
ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
if (ret < 0 && ret != -EINVAL) {
dev_err(&pdev->dev, "failed to parse property %s: %d\n",
propname, ret);
return ret;
}
if (val32 > INT_MAX) {
dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
return -EOVERFLOW;
}
*value = val32;
return 0;
}
static int ramoops_parse_dt(struct platform_device *pdev,
struct ramoops_platform_data *pdata)
{
struct device_node *of_node = pdev->dev.of_node;
struct resource *res;
u32 value;
int ret;
dev_dbg(&pdev->dev, "using Device Tree\n");
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev,
"failed to locate DT /reserved-memory resource\n");
return -EINVAL;
}
pdata->mem_size = resource_size(res);
pdata->mem_address = res->start;
pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
#define parse_size(name, field) { \
ret = ramoops_parse_dt_size(pdev, name, &value); \
if (ret < 0) \
return ret; \
field = value; \
}
parse_size("record-size", pdata->record_size);
parse_size("console-size", pdata->console_size);
parse_size("ftrace-size", pdata->ftrace_size);
parse_size("pmsg-size", pdata->pmsg_size);
parse_size("ecc-size", pdata->ecc_info.ecc_size);
#undef parse_size
return 0;
}
void notrace ramoops_console_write_buf(const char *buf, size_t size)
{
struct ramoops_context *cxt = &oops_cxt;
persistent_ram_write(cxt->cprz, buf, size);
}
static int ramoops_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ramoops_platform_data *pdata = dev->platform_data;
struct ramoops_context *cxt = &oops_cxt;
size_t dump_mem_sz;
phys_addr_t paddr;
int err = -EINVAL;
if (dev_of_node(dev) && !pdata) {
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata) {
err = -ENOMEM;
goto fail_out;
}
err = ramoops_parse_dt(pdev, pdata);
if (err < 0)
goto fail_out;
}
/* Only a single ramoops area allowed at a time, so fail extra
* probes.
*/
if (cxt->max_dump_cnt)
goto fail_out;
if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
!pdata->ftrace_size && !pdata->pmsg_size)) {
pr_err("The memory size and the record/console size must be "
"non-zero\n");
goto fail_out;
}
if (pdata->record_size && !is_power_of_2(pdata->record_size))
pdata->record_size = rounddown_pow_of_two(pdata->record_size);
if (pdata->console_size && !is_power_of_2(pdata->console_size))
pdata->console_size = rounddown_pow_of_two(pdata->console_size);
if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
cxt->size = pdata->mem_size;
cxt->phys_addr = pdata->mem_address;
cxt->memtype = pdata->mem_type;
cxt->record_size = pdata->record_size;
cxt->console_size = pdata->console_size;
cxt->ftrace_size = pdata->ftrace_size;
cxt->pmsg_size = pdata->pmsg_size;
cxt->dump_oops = pdata->dump_oops;
cxt->ecc_info = pdata->ecc_info;
paddr = cxt->phys_addr;
dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
- cxt->pmsg_size;
err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
if (err)
goto fail_out;
err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
cxt->console_size, 0);
if (err)
goto fail_init_cprz;
err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
LINUX_VERSION_CODE);
if (err)
goto fail_init_fprz;
err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
if (err)
goto fail_init_mprz;
cxt->pstore.data = cxt;
/*
* Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
* have to handle dumps, we must have at least record_size buffer. And
* for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
* ZERO_SIZE_PTR).
*/
if (cxt->console_size)
cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
if (!cxt->pstore.buf) {
pr_err("cannot allocate pstore buffer\n");
err = -ENOMEM;
goto fail_clear;
}
spin_lock_init(&cxt->pstore.buf_lock);
cxt->pstore.flags = PSTORE_FLAGS_DMESG;
if (cxt->console_size)
cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
if (cxt->ftrace_size)
cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
if (cxt->pmsg_size)
cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
err = pstore_register(&cxt->pstore);
if (err) {
pr_err("registering with pstore failed\n");
goto fail_buf;
}
/*
* Update the module parameter variables as well so they are visible
* through /sys/module/ramoops/parameters/
*/
mem_size = pdata->mem_size;
mem_address = pdata->mem_address;
record_size = pdata->record_size;
dump_oops = pdata->dump_oops;
ramoops_console_size = pdata->console_size;
ramoops_pmsg_size = pdata->pmsg_size;
ramoops_ftrace_size = pdata->ftrace_size;
pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
cxt->size, (unsigned long long)cxt->phys_addr,
cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
return 0;
fail_buf:
kfree(cxt->pstore.buf);
fail_clear:
cxt->pstore.bufsize = 0;
persistent_ram_free(cxt->mprz);
fail_init_mprz:
persistent_ram_free(cxt->fprz);
fail_init_fprz:
persistent_ram_free(cxt->cprz);
fail_init_cprz:
ramoops_free_przs(cxt);
fail_out:
return err;
}
static int ramoops_remove(struct platform_device *pdev)
{
struct ramoops_context *cxt = &oops_cxt;
pstore_unregister(&cxt->pstore);
kfree(cxt->pstore.buf);
cxt->pstore.bufsize = 0;
persistent_ram_free(cxt->mprz);
persistent_ram_free(cxt->fprz);
persistent_ram_free(cxt->cprz);
ramoops_free_przs(cxt);
return 0;
}
static const struct of_device_id dt_match[] = {
{ .compatible = "ramoops" },
{}
};
static struct platform_driver ramoops_driver = {
.probe = ramoops_probe,
.remove = ramoops_remove,
.driver = {
.name = "ramoops",
.of_match_table = dt_match,
},
};
static void ramoops_register_dummy(void)
{
if (!mem_size)
return;
pr_info("using module parameters\n");
dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
if (!dummy_data) {
pr_info("could not allocate pdata\n");
return;
}
dummy_data->mem_size = mem_size;
dummy_data->mem_address = mem_address;
dummy_data->mem_type = mem_type;
dummy_data->record_size = record_size;
dummy_data->console_size = ramoops_console_size;
dummy_data->ftrace_size = ramoops_ftrace_size;
dummy_data->pmsg_size = ramoops_pmsg_size;
dummy_data->dump_oops = dump_oops;
/*
* For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
* (using 1 byte for ECC isn't much of use anyway).
*/
dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
dummy = platform_device_register_data(NULL, "ramoops", -1,
dummy_data, sizeof(struct ramoops_platform_data));
if (IS_ERR(dummy)) {
pr_info("could not create platform device: %ld\n",
PTR_ERR(dummy));
}
}
static int __init ramoops_init(void)
{
ramoops_register_dummy();
return platform_driver_register(&ramoops_driver);
}
postcore_initcall(ramoops_init);
static void __exit ramoops_exit(void)
{
platform_driver_unregister(&ramoops_driver);
platform_device_unregister(dummy);
kfree(dummy_data);
}
module_exit(ramoops_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");