GCC produces unaligned function address on Cortex M3 - function

I just placed a function to a specific address using a section and then I output the address of that function and the result is the chosen section address + 1.
This is what I did:
void __attribute__((section (".my_fct_address"))) Fct_Ptr_Test (void)
{
...
}
and
void (*fct_ptr) (void);
fct_ptr = Fct_Ptr_Test;
printf ("0X%X\r\n", (uint32_t)(fct_ptr));
fct_ptr ();
in ld-file:
.my_fct_address 0x800F000 :
{
KEEP(*(.my_fct_address)) /* keep my variable even if not referenced */
} > FLASH
The above printf statement outputs 0x800F001 and Fct_Ptr_Test is called properly
If I set
fct_ptr = 0x800F000;
the system crashes.
If I set
fct_ptr = 0x800F001;
everything is fine again.
If I don't place Fct_Ptr_Test in its own section , ie let the linker place it anywhere I also get an odd address.
Now I wonder how 0x800F001 can be a proper address on a 32 bit controller (ARM cortex M3) and what is stored in 0x800F000.
Even more strange: map-file always shows the even addresses
Can anybody help?
Thanks
Martin

Linker sets the least-significant bit of Thumb functions to 1 to facilitate interworking (see docs). Perhaps that's your case?

Related

Putting C++ string in HTML code to show value on webserver

I've set up a webserver running on ESP8266 thats currently hosting 7 sites. The sites is written in plain HTML in each diffrent tab in the arduino ide. I have installed the library Pagebuilder to help with making everything look nice and run.
Except one thing. I have a button connected to my ESP8266 which by the time being imitates a sensor input. basicly when the button is pressed my integer "x" increments with 1. I also managed to make a string that replicates "x" and increments with the same value.
I also have a problem with Printing the IPadresse of the server, but thats not as important as the other.
My plan then was writing the string "score" (which contains x) into the HTML tab where it should be output. this obviously didnt work.
Things I've tried:
Splitting up the HTML code where I want the string to be printed and using client.println("");
This didnt work because the two libraries does not cooperate and WiFiClient does not find Pagebuilders server. (basicly, the client.println does nothing when I used it with Pagebuilder).
Reconstructing the HTML page as a literal really long string, and adding in the String with x like this: "html"+score+"html" and adding it into where the HTML page const char were. (basicly replacing the variable with the text that were in the variable).
This did neighter work because the argument "PageElement" from Pagebuilder does only expect one string, and errors out because theres an additional string inside the HTML string.
I've tried sending it as a post req. but this did not output the value either.
I have run out of Ideas to try.
//root page
#if defined(ARDUINO_ARCH_ESP8266)
#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <WiFiClient.h>
#elif defined(ARDUINO_ARCH_ESP32)
#include <WiFi.h>
#include <WebServer.h>
#endif
#include "PageBuilder.h"
#include "currentGame.h" //tab 1
#if defined(ARDUINO_ARCH_ESP8266)
ESP8266WebServer Server;
ESP8266WebServer server;
#endif
int sensorPin = 2; // button input
int sensorValue = 0;
int x = 0; // the int x
String score=""; //the string x will be in
PageElement CURRENT_GAME_ELEMENT(htmlPage1);
PageBuilder CURRENT_GAME("/current-game", {CURRENT_GAME_ELEMENT}); // this //only showes on href /current-game
void button() {
sensorValue = analogRead(sensorPin); //read the voltage
score="Team 1: "+String((int)x+1); //"make" x a string
if (sensorValue <= 10) { // check if button is pressed
x++; // increment x
Serial.println(x);
Serial.println(score);
delay(100);
}
}
void setup() {
Serial.begin(115200);
pinMode(2, INPUT);
WiFi.softAP("SSID", "PASS");
delay(100);
CURRENT_GAME.insert(Server);
Server.begin();
}
void loop() {
Server.handleClient();
button();
}
// tab 1
const char htmlPage1[] PROGMEM = R"=====(
/*
alot of HTML, basicly the whole website...
..............................................
*/
<div class="jumbotron">
<div align="center">
<h1 class="display-4"> score </h1> // <--- this is where
//I want to print the
//string:
</div>
</div>
)=====";
what I want to do is getting the value of the string score displayed on the website. If I put "score" directly into the HTML, the word score will be displayed, not the value. I want the value displayed.
Edit:
I have figured out how to make the string(score) be printed in the HTML code, thus, I only have to convert the HTML code string back to a char. explanation is in comment below.
Edit 2: (-------------------------solution-------------------------)
Many thanks for the help I've gotten and sorry for being so ignorant, its just so hard being so close and that thing doesnt work. but anyways, What I did was following Pagebuilders example, and making another element to print in current game..
String test(PageArgument& args) {
return score;
}
const char html[] = "<div class=\"jumbotron\"><div align=\"center\"><h1 class=\"display-4\">{{NAME}}</h1></div></div>";
PageElement FRAMEWORK_PAGE_ELEMENT(htmlPage0);
PageBuilder FRAMEWORK_PAGE("/", {FRAMEWORK_PAGE_ELEMENT});
PageElement body_elem(html, { {"NAME", test} });
PageElement CURRENT_GAME_ELEMENT(htmlPage1);
PageBuilder CURRENT_GAME("/current-game", { CURRENT_GAME_ELEMENT, body_elem});
suprisingly easy when I first understood it.. Thanks again.
You could try building your string first, then converting it to a const char
like this: const char * c = str.c_str();
if you can't use a pointer you could try this:
string s = "yourHTML" + score + "moreHTML";
int n = s.length();
char char_array[n + 1];
strcpy(char_array, s.c_str());
additionally you could try the stringstream standard library
This sort of thing is often done using magic tags in your markup that are detected by the server code before it serves the HTML and filled in by executing some sort of callback or filling in a variable, or whatever.
So with this in mind and hoping for the best, I nipped over to: PageBuilder on github and looked to see if there was something similar here. Good news! In one of the examples:
const char html[] = "hello <b>{{NAME}}</b>, <br>Good {{DAYTIME}}.";
...
PageElement body_elem(html, { {"NAME", AsName}, {"DAYTIME", AsDayTime} });
Where {{NAME}} and {{DAYTIME}} are magic tokens. AsName and AsDayTime are functions to be called when the respective tag is encountered while the page is being served.
EDIT: in response to a request to explain differently, I'm not convinced I can do a better job of explaining the code than the example on the library's own github page, so I'll try a wordy description instead:
When you want to serve a webpage to a client, the code needs to know what you want to serve. In the simplest case, it's a static page: the same every time. You can just write the HTML, stick it in a string an be done.
whole_page = "<html>My fixed content</html>";
webserver.serve(whole_page);
But you want some dynamic element(s). As noted, you can do it in a few ways, such as serving some static HTML, then the dynamic bit, then some more static HTML. It seems you've not had much luck like this, and it's rather clunky anyway.
Or you can pre-build a new string out of the three bits and serve that in one chunk, but that's also pretty clunky.
(Aside: taking big strings and adding them together is likely to be slow and memory intensive, two things you really don't want on a little CPU like the ESP8266).
So instead, you allow 'magic' markers in the HTML, using a marker in place of the dynamic content, and serve that instead.
whole_page = "<html>My dynamic content. Value is {{my_value}}</html>";
webserver.serve(whole_page, ...);
The clever bit is that as the page is being served, the webserver is watching the text go by, and when it sees a magic tag, it stops and asks you to fill in the blank, then carries on as before.
Obviously, there is some processing overhead with watching for tags, and some programming overhead with telling it what tags to watch for and how to ask you for the data it needs.
I got advice from a friend who told me I should make a unique argument where I wanted the string(x) and then using some syntax to replace it. I also took inspiration from you Jelle..
what I did was make a unique argument "VAR_CURRENT_SCORE" put that into the HTML where I want the score output, then convert htmlPage1 from a char to a string, use string.replace() and replace "VAR_CURRENT_SCORE" with the string(x) score. this workes as I can see in the serial monitor output.
This is what I did:
//root page
String HTMLstring(htmlstringPage);
delay(100);
HTMLstring.replace("VAR_CURRENT_SCORE", score);
delay(50);
Serial.println("string:");
Serial.println(HTMLstring);
//tab 1 char htmlstringPage[] PROGMEM = R"=====(
<div class="jumbotron">
<div align="center">
<h1 class="display-4">VAR_CURRENT_SCORE</h1>
</div>
</div>
)=====";
However, I still have a small problem left which is converting the string back to char to post it to the website.
To convert the string back:
request->send_P(200, "text/html", HTMLstring.c_str());

How to use a signal as function parameter in CAPL

I am trying to write a function in CAPL that takes a signal and calculates the physical value with the signal value, the signal factor and the signal offset.
This is how a simple gateway normally works:
message CAN1.myMessage1 myMessage1 = {DIR = RX};//message from the database
message CAN2.myMessage2 myMessage2 = {DIR = TX};//another message from the database
on message CAN1.*
{
if(this.id == myMessage1.id)
{
myMessage1 = this;
myMessage2.mySignalB = myMessage1.mySignalA * myMessage1.mySignalA.factor + myMessage1.mySignalA.offset;
}
}
And this is what I am trying to do:
...
on message CAN1.*
{
if(this.id ==myMessage1.id)
{
myMessage1 = this;
myMessage2.mySignalB = PhysicalValue(myMessage1.mySignalA);
}
}
double PhysicalValue(signal * s)
{
return s*s.factor+s.offset;
}
There are two problems with this code:
Firstly when I pass the signal as the parameter the compiler says that the types don't match. The second problem is that inside the function the attributes (factor and offset) are no longer recognized.
These problems might have something to do with the weird object-oriented-but-not-really nature of CAPL. The value of the signals can be accessed directly but it also has attributes?
int rawValue = myMessage1.mySignalA;
If you are familiar with C you might say that the problem is that I am specifying a pointer in the function but that I am not passing a pointer into it. But in CAPL there are no pointers and the * simply means anything.
Without the * I would have needed to use a specific signal which would have defeated the purpose of the function.
EDIT:
I have found the attribute .phys by now which does exactly what my demo function would have done.
double physValue = myMessage1.mySignalA.phys;
This has already made my code much shorter but there are other operations that I need to perform for multiple signals so being able to use signals as a function parameter would still be useful.
What you can do is this:
double PhysicalValue(signal * s)
{
// access signal by prepending a $
return $s.phys;
}
Call like this
on message CAN1.*
{
if(this.id ==myMessage1.id)
{
myMessage1 = this;
myMessage2.mySignalB = PhysicalValue(CAN1::myMessage1::mySignalA);
}
}
I.e. when you call your function, you have to provide the qualified name of the signal (with colons rather than dots). To my knowledge it is not possible to use myMessage1.mySignalA, since signals itself are not a CAPL datatype.
Apart from this, you might re-think whether you really should be using on message, but rather switch to on signal. Handling the signal values no matter with which message they are sent is done by CANoe's signal server.
Note that CANoe already has a function which does exactly what you're trying to do (multiplying by factor and adding offset). It's called getSignal:
on message CAN1.*
{
if(this.id == myMessage1.id)
{
myMessage2.mySignalB = getSignal(myMessage1::mySignalA);
}
}
Offsets and factors are defined in e.g. the DBC files.

Equivalent of Platform::IBoxArray in C++/WinRT

I am currently porting an UWP application from C++/CX to C++/WinRT. I encountered a safe_cast<Platform::IBoxArray<byte>^>(data) where data is of type Windows::Foundation::IInspectable ^.
I know that the safe_cast is represented by the as<T> method, and I know there are functions for boxing (winrt::box_value) and unboxing (winrt::unbox_value) in WinRT/C++.
However, I need to know the equivalent of Platform::IBoxArray in order to perform the cast (QueryInterface). According to https://learn.microsoft.com/de-de/cpp/cppcx/platform-iboxarray-interface?view=vs-2017, IBoxArray is the C++/CX equivalent of Windows::Foundation::IReferenceArray, but there is no winrt::Windows::Foundation::IReferenceArray...
Update for nackground: What I am trying to achieve is retrieving the view transform attached by the HoloLens to every Media Foundation sample from its camera. My code is based on https://github.com/Microsoft/HoloLensForCV, and I got really everything working except for this last step. The problem is located around this piece of code:
static const GUID MF_EXTENSION_VIEW_TRANSFORM = {
0x4e251fa4, 0x830f, 0x4770, 0x85, 0x9a, 0x4b, 0x8d, 0x99, 0xaa, 0x80, 0x9b
};
// ...
// In the event handler, which receives const winrt::Windows::Media::Capture::Frames::MediaFrameReader& sender:
auto frame = sender.TryAcquireLatestFrame();
// ...
if (frame.Properties().HasKey(MF_EXTENSION_VIEW_TRANSFORM)) {
auto /* IInspectable */ userData = frame.Properties().Lookup(MF_EXTENSION_VIEW_TRANSFORM);
// Now I would have to do the following:
// auto userBytes = safe_cast<Platform::IBoxArray<Byte> ^>(userData)->Value;
//viewTransform = *reinterpret_cast<float4x4 *>(userBytes.Data);
}
I'm also working on porting some code from HoloLensForCV to C++/WinRT. I came up with the following solution for a very similar case (but not the exact same line of code you ask about):
auto user_data = source.Info().Properties().Lookup(c_MF_MT_USER_DATA); // type documented as 'array of bytes'
auto source_name = user_data.as<Windows::Foundation::IReferenceArray<std::uint8_t>>(); // Trial and error to get the right specialization of IReferenceArray
winrt::com_array<std::uint8_t> arr;
source_name.GetUInt8Array(arr);
winrt::hstring source_name_str{ reinterpret_cast<wchar_t*>(arr.data()) };
Specifically, you can replace the safe_cast with .as<Windows::Foundation::IReferenceArray<std::uint8_t> for a boxed array of bytes. Then, I suspect doing the same cast as me (except to float4x4* instead of wchar_t*) will work for you.
The /ZW flag is not required for my example above.
I can't believe that actually worked, but using information from https://learn.microsoft.com/de-de/windows/uwp/cpp-and-winrt-apis/interop-winrt-cx, I came up with the following solution:
Enable "Consume Windows Runtime Extension" via /ZW and use the following conversion:
auto abi = reinterpret_cast<Platform::Object ^>(winrt::get_abi(userData));
auto userBytes = safe_cast<Platform::IBoxArray<byte> ^>(abi)->Value;
viewTransform = *reinterpret_cast<float4x4 *>(userBytes->Data);
Unfortunately, the solution has the drawback of generating
warning C4447: 'main' signature found without threading model. Consider using 'int main(Platform::Array^ args)'.
But for now, I can live with it ...

aws-sdk-cpp: how to use CurlHttpClient?

I need to make signed requests to AWS ES, but am stuck at the first hurdle in that I cannot seem to be able to use CurlHttpClient. Here is my code (verb, path, and body defined elsewhere):
Aws::Client::ClientConfiguration clientConfiguration;
clientConfiguration.scheme = Aws::Http::Scheme::HTTPS;
clientConfiguration.region = Aws::Region::US_EAST_1;
auto client = Aws::MakeShared<Aws::Http::CurlHttpClient>(ALLOCATION_TAG, clientConfiguration);
Aws::Http::URI uri;
uri.SetScheme(Aws::Http::Scheme::HTTPS);
uri.SetAuthority(ELASTIC_SEARCH_DOMAIN);
uri.SetPath(path);
Aws::Http::Standard::StandardHttpRequest req(uri, verb);
req.AddContentBody(body);
auto res = client->MakeRequest(req);
Aws::Http::HttpResponseCode resCode = res->GetResponseCode();
if (resCode == Aws::Http::HttpResponseCode::OK) {
Aws::IOStream &body = res->GetResponseBody();
rejoiceAndBeMerry();
}
else {
gotoPanicStations();
}
When executed, the code throws a bad_function_call deep from within the sdk mixed up with a lot of shared_ptr this and allocate that. My guess is that I am just using the SDK wrong, but I've been unable to find any examples that use the CurlHttpClient directly such as I need to do here.
How can I use CurlHttpClient?
You shouldn't be using the HTTP client directly, but the supplied wrappers with the aws-cpp-sdk-es package. Like previous answer(s), I would recommend evaluating the test cases shipped with the library to see how the original authors intended to implement the API (at least until the documents catch-up).
How can I use CurlHttpClient?
Your on the right track with managed shared resources and helper functions. Just need to create a static factory/client to reference. Here's a generic example.
using namespace Aws::Client;
using namespace Aws::Http;
static std::shared_ptr<HttpClientFactory> MyClientFactory; // My not be needed
static std::shared_ptr<HttpClient> MyHttpClient;
// ... jump ahead to method body ...
ClientConfiguration clientConfiguration;
MyHttpClient = CreateHttpClient(clientConfiguration);
Aws::String uri("https://example.org");
std::shared_ptr<HttpRequest> req(
CreateHttpRequest(uri,
verb, // i.e. HttpMethod::HTTP_POST
Utils::Stream::DefaultResponseStreamFactoryMethod));
req.AddContentBody(body); //<= remember `body' should be `std::shared_ptr<Aws::IOStream>',
// and can be created with `Aws::MakeShared<Aws::StringStream>("")';
req.SetContentLength(body_size);
req.SetContentType(body_content_type);
std::shared_ptr<HttpResponse> res = MyHttpClient->MakeRequest(*req);
HttpResponseCode resCode = res->GetResponseCode();
if (resCode == HttpResponseCode::OK) {
Aws::StringStream resBody;
resBody << res->GetResponseBody().rdbuf();
rejoiceAndBeMerry();
} else {
gotoPanicStations();
}
I encountered exactly the same error when trying to download from S3 using CurlHttpClient.
I fixed it by instead modelling my code after the integration test found in the cpp sdk:
aws-sdk-cpp/aws-cpp-sdk-s3-integration-tests/BucketAndObjectOperationTest.cpp
Search for the test called TestObjectOperationsWithPresignedUrls.

Flash ABC : What does the number part of <file>.as$<number> in a swfdump

If I take a swf, and run it through swfdump
swfdump.exe -abc file.swf > ABC.txt
One the first run I may get some output in ABC.txt like this
ObjectConfig.as$60
And on a subsequent run of the same SWF get a different output
ObjectConfig.as$61
What is the meaning of the number after the $ ?
This is part of the debug metadata that the mxmlc compiler adds to the bytecode when you do a debug compile, debug=true. If you do a normal release compile, this info is omitted.
This metadata stores filenames and line numbers so that you can see the location in your source while debugging. Although I'm not sure on the exact meaning of these particular numbers, they seem to be a unique identifier or index of that file for the debugger, perhaps in case of two classes with the same name.
The best I can see is in the source code for swfdump, it calls swf_GetString. Somewhere in this chain it adds what looks like a debugLine or a scopeDepth to the end of the class name:
char* swf_GetString(TAG*t)
{
int pos = t->pos;
while(t->pos < t->len && swf_GetU8(t));
/* make sure we always have a trailing zero byte */
if(t->pos == t->len) {
if(t->len == t->memsize) {
swf_ResetWriteBits(t);
swf_SetU8(t, 0);
t->len = t->pos;
}
t->data[t->len] = 0;
}
return (char*)&(t->data[pos]);
}