Adding Embedded Linux platform #1480

linfan68 · 2025-04-03T15:59:39Z

This pull request introduces support for the linemb platform, targeting embedded Linux devices such as the Raspberry Pi Zero. The changes include updates to several configuration and source files to ensure compatibility and functionality for this new platform.
The original disscussion: Running on ARM Linux boards (Raspberry Pi Zero)

The most important changes are summarized below:

Main Entrance for new platform:

build/devices/linemb/xsProj-glib/main.c: The main entrance for the new platform. Also added signal handling, timeout management, and stack trace functionality to improve error handling and debugging capabilities on the new linemb platform, refer to discussion here: Exception message from JS not showing in log #1474.

Build System:

Added tools/mcconfig/make.linemb.mk to define the build process for the linemb platform, including toolchain configurations and compilation flags.

Platform-Specific Headers:

Added a new platform header file xs/platforms/linemb/xsPlatform_linemb.h to define platform-specific macros and include necessary headers for the linemb platform.

Platform Support:

Added linemb platform configuration in various manifest.json files to include necessary modules and settings for the linemb platform. [1] [2] [3] [4] [5] [6] [7] [8] [9]

Documentation:

Created a new documentation file documentation/devices/linemb.md to guide users on setting up and using the Moddable SDK with embedded Linux devices. This includes preparation steps, toolchain installation, and sample project build instructions.

…ed modules.

linfan68 · 2025-04-05T00:39:00Z

I will add this for "why we need this new platform?" in the linemb.md file. Please also comment on new use cases:

Ultra-Low Resource Consumption on Small Linux Devices
Moddable's embedded JS runtime requires minimal memory and CPU resources compared to Node.js, making it ideal for resource-constrained IoT devices. For example, Node.js processes in production environments often consume 200MB+ RSS memory, while Moddable operates efficiently even on microcontrollers like ESP32. Its lightweight architecture (designed for low-cost hardware) enables faster startup times and lower RAM/ROM footprints.
Single-Executable Deployment
The platform eliminates dependency sprawl by bundling all required components into one self-contained executable. This contrasts with Node.js' heavy reliance on npm modules and system libraries. Moddable's integrated SDK approach ensures portable deployment without complex environment configurations.
Seamless C Language Interoperability
Native extensions in Moddable require minimal boilerplate compared to Node.js' N-API/V8 binding complexities. Developers can directly invoke C functions from JavaScript via XS engine bindings, similar to embedded C development paradigms. This enables hybrid apps combining JS logic with hardware-level C optimizations and hardware operation.
Cross-Environment Testing via Hardware Abstraction
With a robust Hardware Abstraction Layer (HAL), automated tests targeting embedded devices can run unmodified on Linux servers for CI/CD pipelines.

phoddie

Overall this looks quite good. Please let me know if you have any questions about the comments.

phoddie · 2025-04-21T17:34:09Z

build/devices/linemb/xsProj-glib/main.c

+
+  c_memset(the, 0, sizeof(txMachine));
+  the->preparation = preparation;
+  the->keyArray = preparation->keys;
+  the->keyCount = (txID)preparation->keyCount + (txID)preparation->creation.initialKeyCount;
+  the->keyIndex = (txID)preparation->keyCount;
+  the->nameModulo = preparation->nameModulo;
+  the->nameTable = preparation->names;
+  the->symbolModulo = preparation->symbolModulo;
+  the->symbolTable = preparation->symbols;
+
+  the->stack = &preparation->stack[0];
+  the->stackBottom = &preparation->stack[0];
+  the->stackTop = &preparation->stack[preparation->stackCount];
+
+  the->firstHeap = &preparation->heap[0];
+  the->freeHeap = &preparation->heap[preparation->heapCount - 1];
+  the->aliasCount = (txID)preparation->aliasCount;
+
+  setvbuf(stdout, NULL, _IONBF, 0);
+  the = fxCloneMachine(&preparation->creation, the, "linemb", NULL);


This is more-or-less xsPrepareMachine (implemented in fxPrepareMachine). If possible, it would be more maintainable to use the xsPrepareMachine.

build/devices/linemb/xsProj-glib/main.c

phoddie · 2025-04-21T17:38:32Z

build/devices/linemb/xsProj-glib/main.c

+const char *gXSAbortStrings[] ICACHE_FLASH_ATTR = {
+	"debugger",
+	"memory full",
+	"stack overflow",
+	"fatal",
+	"dead strip",
+	"unhandled exception",
+	"not enough keys",
+	"too much computation",
+	"unhandled rejection"
+};


You could use fxAbortString() instead of maintaining your own list of abort strings (the function was added very recently)

phoddie · 2025-04-21T17:39:12Z

build/devices/linemb/xsProj-glib/main.c

+void fxAbort(xsMachine *the, int status)
+{
+  const char *msg = (status <= XS_UNHANDLED_REJECTION_EXIT) ? gXSAbortStrings[status] : "unknown";
+#if 0 // MODDEF_XS_ABORTHOOK


I recall you had a question about the abort hook. Is this disabled because you weren't able to resolve that?

@phoddie Actually the abort hook works... But I was having trouble figuring out how to make MODDEF_XS_ABORTHOOK defined... somehow adding this

"defines": { "xs": { "abortHook": 1 } }

does not get MODDEF_XS_ABORTHOOK defined

MODDEF_XS_ABORTHOOK should be defined in mc.defines.h. It looks like main.c isn't including that?

#include "mc.defines.h"

xs/platforms/xsHost.h

phoddie · 2025-04-21T17:44:12Z

build/devices/linemb/xsProj-glib/main.c

+static void fatal_error_handler(int signum) {
+  const char* signame = "UNKNOWN";
+  switch(signum) {
+    case SIGABRT: signame = "SIGABRT"; break;
+    case SIGFPE:  signame = "SIGFPE"; break;
+    case SIGILL:  signame = "SIGILL"; break;
+    case SIGINT:  signame = "SIGINT"; break;
+    case SIGQUIT: signame = "SIGQUIT"; break;
+    case SIGSEGV: signame = "SIGSEGV"; break;
+    case SIGTERM: signame = "SIGTERM"; break;
+    case SIGBUS:  signame = "SIGBUS"; break;
+    case SIGPIPE: signame = "SIGPIPE"; break;
+  }


Is strsignal() an option here?

phoddie · 2025-04-21T17:49:31Z

examples/helloworld/manifest.json

+	"platforms": {
+		"linemb/*": {
+			"strip": []
+		}


"helloworld", and most applications, shouldn't need a platform specific section of its manifest.

Actually I have a question here. After syncing recent code, I'm getting "Aborting with status 4, dead strip" error, unless adding this config to disable stripping. I assume there are some book keeping logic mssing here.

On the other hand, given there should be (relatively) plenty of memory on those linux chips, it might be a good idea to disable stripping?

After syncing recent code, I'm getting "Aborting with status 4, dead strip" error, unless adding this config to disable stripping. I assume there are some book keeping logic missing here.

I wonder if that is because you allow for top-level await in the host (which is fine) but no script uses a promise or async/await (for example, in helloworld).

On the other hand, given there should be (relatively) plenty of memory on those linux chips, it might be a good idea to disable stripping?

Your host can certainly make that choice. A project can still enable engine stripping if it wants to. The default for "strip" is set in manifest_base.json. I think you can simply override that in your host's manifest.

phoddie · 2025-04-21T17:50:36Z

documentation/devices/linemb.md

@@ -0,0 +1,129 @@
+# Using the Moddable SDK with embedded Linux (Raspberry Pi Zero)
+This is a demo document to demostration how to bring up an embedded Linux device with the Moddable SDK.


"demonstrate" in place of "demostration"

build/devices/linemb/manifest.json

phoddie · 2025-04-30T23:50:06Z

@linfan68 – we were thinking we could include this in our May release if you are able to resolve the comments.. Any chance of that in the coming days? Thanks!

mkellner · 2025-05-04T23:07:16Z

Hello @linfan68. I am trying with Ubuntu 22.04.4 LTS x86_64 host.

I get this error trying to build linemb/armhf

.../moddable/xs/platforms/lin_xs.h:57:10: fatal error: gio/gio.h: No such file or directory
   57 | #include <gio/gio.h>

linfan68 · 2025-05-12T16:32:48Z

@linfan68 – we were thinking we could include this in our May release if you are able to resolve the comments.. Any chance of that in the coming days? Thanks!

Sorry I just had a crazy week.... sure I'll try to resolve these comments in the coming days.

…call

linfan68 · 2025-05-12T17:12:15Z

#include <gio/gio.h>

HI @mkellner , where did you see this error? When building moddable tools?

linfan68 · 2025-05-12T17:16:40Z

@linfan68 – we were thinking we could include this in our May release if you are able to resolve the comments.. Any chance of that in the coming days? Thanks!

I've resolved most of the comments. Also fixed an issue that caused 100% cpu... faeec84

I'll test the error handling code a little bit before finalized this PR. Also please give me some pointers on the abortHook issue I mentioned above。

mkellner · 2025-05-13T17:17:37Z

#include <gio/gio.h>

HI @mkellner , where did you see this error? When building moddable tools?

No. This was buildhost: Ubuntu 22.04.4 LTS, target: linemb/arm64 building helloworld.

linfan68 · 2025-05-14T14:20:18Z

#include <gio/gio.h>

HI @mkellner , where did you see this error? When building moddable tools?

No. This was buildhost: Ubuntu 22.04.4 LTS, target: linemb/arm64 building helloworld.

Found the problem, you need glib for arm64

sudo apt-get install libglib2.0-dev:arm64

I'll update the document

Fan LIN and others added 4 commits May 14, 2024 06:15

Linux Embeded demo

90e1336

Merge branch 'Moddable-OpenSource:public' into linemb-demo

2b384fe

adding linemb support and documents

f5aec72

Guide for handling "module not found" issue. And add support for test…

2c2dba0

…ed modules.

phoddie reviewed Apr 21, 2025

View reviewed changes

Fan Lin added 6 commits May 12, 2025 16:41

using fxPrepareMachine

6652284

Fixed busy waiting issue by using blocked g_main_context_iteration() …

faeec84

…call

Merge remote-tracking branch 'origin/public' into linemb-demo

b345ce5

move "strip": [] into manifest_base.json

63a8c40

using strsignal()

d092525

typo in linemb.md

71209e5

		@@ -0,0 +1,129 @@
		# Using the Moddable SDK with embedded Linux (Raspberry Pi Zero)
		This is a demo document to demostration how to bring up an embedded Linux device with the Moddable SDK.

Adding Embedded Linux platform #1480

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Adding Embedded Linux platform #1480

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Conversation

linfan68 commented Apr 3, 2025

Main Entrance for new platform:

Build System:

Platform-Specific Headers:

Platform Support:

Documentation:

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linfan68 commented Apr 5, 2025

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phoddie commented Apr 30, 2025

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mkellner commented May 4, 2025

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linfan68 commented May 12, 2025

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linfan68 commented May 12, 2025

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linfan68 commented May 12, 2025

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mkellner commented May 13, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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linfan68 commented May 14, 2025

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mkellner commented May 13, 2025 •

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