Skip to content
GitLab
Explore
Sign in
Primary navigation
Search or go to…
Project
E
embedded-linux
Manage
Activity
Members
Labels
Plan
Issues
Issue boards
Milestones
Wiki
Code
Merge requests
Repository
Branches
Commits
Tags
Repository graph
Compare revisions
Snippets
Build
Pipelines
Jobs
Pipeline schedules
Artifacts
Deploy
Releases
Package registry
Container registry
Model registry
Operate
Environments
Terraform modules
Monitor
Incidents
Service Desk
Analyze
Value stream analytics
Contributor analytics
CI/CD analytics
Repository analytics
Model experiments
Help
Help
Support
GitLab documentation
Compare GitLab plans
GitLab community forum
Contribute to GitLab
Provide feedback
Terms and privacy
Keyboard shortcuts
?
Snippets
Groups
Projects
Show more breadcrumbs
David Maul
embedded-linux
Commits
dcf30472
Commit
dcf30472
authored
4 months ago
by
David Maul
Browse files
Options
Downloads
Patches
Plain Diff
fix: prepare message only once for sending
parent
313987fc
No related branches found
No related tags found
No related merge requests found
Changes
1
Show whitespace changes
Inline
Side-by-side
Showing
1 changed file
kernel/kmod.c
+46
-26
46 additions, 26 deletions
kernel/kmod.c
with
46 additions
and
26 deletions
kernel/kmod.c
+
46
−
26
View file @
dcf30472
...
...
@@ -17,7 +17,7 @@
#define SLOTS 4
#define SLOT_INTERVAL_NS 10000000
#define MAX_
VALUE
S 16
#define MAX_
MEASUREMENT
S 16
#define BAUD_RATE 9600
#define BIT_TIME_US (1000000 / BAUD_RATE)
...
...
@@ -28,6 +28,7 @@ static struct class *class = NULL;
static
struct
cdev
mycdev
;
typedef
struct
packet
{
uint8_t
magic
;
data_t
data
;
uint32_t
crc
;
}
packet_t
;
...
...
@@ -42,19 +43,48 @@ static struct task_struct *timed_thread;
static
DECLARE_WAIT_QUEUE_HEAD
(
wq
);
static
atomic_t
wake_counter
=
ATOMIC_INIT
(
0
);
#define SEND_BUFFER_SIZE 4096
static
uint8_t
send_buffer
[
SEND_BUFFER_SIZE
];
static
size_t
send_buffer_size
=
0
;
static
int
slot
=
0
;
static
int
device_open
(
struct
inode
*
inode
,
struct
file
*
file
)
{
return
0
;
}
static
int
device_release
(
struct
inode
*
inode
,
struct
file
*
file
)
{
return
0
;
}
static
uint32_t
calculate_crc32
(
const
data_t
*
data
)
{
uint32_t
crc
=
crc32
(
0
,
(
void
*
)
&
data
->
sender_id
,
sizeof
(
uint8_t
));
crc
=
crc32
(
crc
,
(
void
*
)
&
data
->
count
,
sizeof
(
uint8_t
));
crc
=
crc32
(
crc
,
(
void
*
)
&
data
->
measurements
,
sizeof
(
measurement_t
)
*
data
->
count
);
static
uint32_t
calculate_crc32
(
const
packet_t
*
packet
)
{
uint32_t
crc
=
crc32
(
0
,
(
void
*
)
&
packet
->
data
.
sender_id
,
sizeof
(
uint8_t
));
crc
=
crc32
(
crc
,
(
void
*
)
&
packet
->
data
.
count
,
sizeof
(
uint8_t
));
crc
=
crc32
(
crc
,
(
void
*
)
&
packet
->
data
.
measurements
,
sizeof
(
measurement_t
)
*
packet
->
data
.
count
);
return
crc
;
}
static
void
prepare_for_sending
(
void
)
{
packet
->
crc
=
calculate_crc32
(
packet
);
send_buffer
[
0
]
=
packet
->
magic
;
send_buffer
[
1
]
=
packet
->
data
.
sender_id
;
send_buffer
[
2
]
=
packet
->
data
.
count
;
uint8_t
*
bytes
=
(
uint8_t
*
)
packet
->
data
.
measurements
;
for
(
size_t
i
=
0
;
i
<
sizeof
(
measurement_t
)
*
packet
->
data
.
count
;
i
++
)
{
send_buffer
[
bytes
[
3
+
i
]]
=
bytes
[
i
];
}
bytes
=
(
uint8_t
*
)
&
packet
->
crc
;
for
(
size_t
i
=
0
;
i
<
sizeof
(
uint32_t
);
i
++
)
{
send_buffer
[
3
+
sizeof
(
measurement_t
)
*
packet
->
data
.
count
+
i
]
=
bytes
[
i
];
}
send_buffer_size
=
3
+
sizeof
(
measurement_t
)
*
packet
->
data
.
count
+
sizeof
(
uint32_t
);
}
static
ssize_t
device_write
(
struct
file
*
filp
,
const
char
*
input
,
size_t
length
,
loff_t
*
offset
)
{
if
(
length
!=
sizeof
(
data_t
))
{
...
...
@@ -62,8 +92,8 @@ static ssize_t device_write(struct file *filp, const char *input, size_t length,
return
-
EFAULT
;
}
if
(((
data_t
*
)
input
)
->
count
>=
MAX_
VALUE
S
)
{
printk
(
KERN_ALERT
"lkm: Tried to write more me
ssage
s than allowed
\n
"
);
if
(((
data_t
*
)
input
)
->
count
>=
MAX_
MEASUREMENT
S
)
{
printk
(
KERN_ALERT
"lkm: Tried to write more me
asurement
s than allowed
\n
"
);
return
-
EFAULT
;
}
...
...
@@ -84,7 +114,7 @@ static ssize_t device_write(struct file *filp, const char *input, size_t length,
return
-
EFAULT
;
}
p
acket
->
crc
=
calculate_crc32
(
&
packet
->
data
);
p
repare_for_sending
(
);
printk
(
KERN_INFO
"lkm: received write of size %zu
\n
"
,
length
);
...
...
@@ -123,23 +153,9 @@ static inline void send_byte(uint8_t byte) {
}
static
void
send_data
(
const
packet_t
*
packet
)
{
send_byte
(
0xAA
);
/*
send_byte(packet->data.sensor_id);
send_byte(packet->data.count);
uint8_t *bytes = (uint8_t *)packet->data.values;
for (size_t i = 0; i < sizeof(message_t) * packet->data.count; i++) {
send_byte(bytes[i]);
for
(
size_t
i
=
0
;
i
<
send_buffer_size
;
i
++
)
{
send_byte
(
send_buffer
[
i
]);
}
bytes = (uint8_t *)&packet->crc;
for (size_t i = 0; i < sizeof(uint32_t); i++) {
send_byte(bytes[i]);
}
*/
}
static
int
timed_thread_fn
(
void
*
args
)
{
...
...
@@ -166,16 +182,20 @@ static int __init lkm_init(void) {
return
-
EFAULT
;
}
packet
->
magic
=
0xAA
;
packet
->
data
.
sender_id
=
SENDER_ID
;
packet
->
data
.
count
=
0
;
packet
->
data
.
measurements
=
(
measurement_t
*
)
vmalloc
(
sizeof
(
measurement_t
)
*
MAX_VALUES
);
packet
->
data
.
measurements
=
(
measurement_t
*
)
vmalloc
(
sizeof
(
measurement_t
)
*
MAX_MEASUREMENTS
);
if
(
packet
->
data
.
measurements
==
NULL
)
{
vfree
(
packet
);
return
-
EFAULT
;
}
prepare_for_sending
();
// Dynamically allocate major number
if
(
alloc_chrdev_region
(
&
dev
,
0
,
1
,
DEVICE_NAME
)
<
0
)
{
vfree
(
packet
->
data
.
measurements
);
...
...
This diff is collapsed.
Click to expand it.
Preview
0%
Loading
Try again
or
attach a new file
.
Cancel
You are about to add
0
people
to the discussion. Proceed with caution.
Finish editing this message first!
Save comment
Cancel
Please
register
or
sign in
to comment