Experimental Physics and Industrial Control System
Possible usage of IMFS came up in a recent tech-talk thread[1]. I tried again to make
use of the logic in initialize_local_filesystem() from rtems_init.c, and this time was
successful. Although with some caveats.
As far as I can tell, only the uC5282 target provides special symbols _DownloadLocation,
_FlashBase, and _FlashSize. I found a archived mail from Eric Norum [2] which gives a
hint about how he meant this to be used
> I do this for my standalone EPICS applications by concatenating the tar file at the end of the bootstrap flash. ...
I couldn't figure out how to make use of this logic as is with pc386 (QEMU). By changing
the pointer gymnastics to something simpler I was able to load a tar containing an st.cmd
and a .dbd file. (see attached)
I don't think the idea of concatenating an FS image to an ELF executable or .boot file
can be generalized though.
Linking a tar into an executable can be generalized, but means an executable for each
IOC instance, which seems kind of awkward.
The use of rtems_tarfs_load() also carries a couple of surprises.
1. The 'tar_size' argument is actually not a size, but an upper bound address.
2. Missing directories are not created automatically, and files in them are silently ignored.
eg. "tar -cf image.tar dbd/foo.dbd st.cmd" results in a tar with only two REGTYPE
entries, and no DIRTYPE entry. "tar -xf" will automatically create "dbd/", but
rtems_tarfs_load() does not. Further, "foo.dbd" is then ignored without error.
It took me awhile to figure out what was going on...
This can be worked around by "tar -cf image.tar dbd st.cmd", or more explicitly
"tar --no-recursion -cf image.tar dbd dbd/foo.dbd st.cmd", to include an DIRTYPE
entry for "dbd". (without necessarily including all of its contents.)
[1] https://epics.anl.gov/tech-talk/2021/msg01192.php
[2] https://lists.rtems.org/pipermail/users/2010-March/055394.html
diff --git a/modules/libcom/RTEMS/rtems_init.c b/modules/libcom/RTEMS/rtems_init.c
index c5079b858..aaccdf3b2 100644
--- a/modules/libcom/RTEMS/rtems_init.c
+++ b/modules/libcom/RTEMS/rtems_init.c
@@ -155,32 +155,47 @@ epicsRtemsMountLocalFilesystem(char **argv)
static int
initialize_local_filesystem(char **argv)
{
+#if 0
+ // uC5282 only
extern char _DownloadLocation[] __attribute__((weak));
extern char _FlashBase[] __attribute__((weak));
extern char _FlashSize[] __attribute__((weak));
+ extern char _edata[];
+ int imageValid = _FlashSize && (_DownloadLocation || _FlashBase;
+ char *imageBase = _FlashBase + _edata - _DownloadLocation;
+ size_t imageSize = (size_t)_FlashSize - (_edata - _DownloadLocation);
+#else
+ extern char _FSImageLocation[] __attribute__((weak));
+ extern char _FSImageEnd[] __attribute__((weak));
+ int imageValid = _FSImageLocation && _FSImageEnd;
+ char *imageBase = _FSImageLocation;
+ size_t imageSize = _FSImageEnd-_FSImageLocation;
+#endif
+ const char* cmdline = rtems_bsdnet_bootp_cmdline ? rtems_bsdnet_bootp_cmdline : "./st.cmd";
+ argv[0] = rtems_bsdnet_bootp_boot_file_name ? rtems_bsdnet_bootp_boot_file_name : "epics.boot";
- argv[0] = rtems_bsdnet_bootp_boot_file_name;
if (epicsRtemsMountLocalFilesystem(argv)==0) {
return 1; /* FS setup successful */
- } else if (_FlashSize && (_DownloadLocation || _FlashBase)) {
- extern char _edata[];
- size_t flashIndex = _edata - _DownloadLocation;
- char *header = _FlashBase + flashIndex;
- if (memcmp(header + 257, "ustar ", 8) == 0) {
+ } else if (imageBase) {
+ if (memcmp(imageBase + 257, "ustar ", 8) == 0) {
int fd;
printf ("***** Unpack in-memory file system (IMFS) *****\n");
- if (rtems_tarfs_load("/", (unsigned char *)header, (size_t)_FlashSize - flashIndex) != 0) {
+ if (rtems_tarfs_load("/", (unsigned char *)imageBase, imageSize) != 0) {
printf("Can't unpack tar filesystem\n");
return 0;
}
- if ((fd = open(rtems_bsdnet_bootp_cmdline, 0)) >= 0) {
+ if ((fd = open(cmdline, 0)) >= 0) {
close(fd);
- printf ("***** Found startup script (%s) in IMFS *****\n", rtems_bsdnet_bootp_cmdline);
- argv[1] = rtems_bsdnet_bootp_cmdline;
+ printf ("***** Found startup script (%s) in IMFS *****\n", cmdline);
+ argv[1] = cmdline;
return 1;
}
- printf ("***** Startup script (%s) not in IMFS *****\n", rtems_bsdnet_bootp_cmdline);
+ printf ("***** Startup script (%s) not in IMFS *****\n", cmdline);
+ return 1; /* FS setup successful */
+
+ } else {
+ printf ("***** IMFS image @%p is not a ustar, ignoring *****\n", imageBase);
}
}
return 0;
/* fooMain.cpp */
/* Author: Marty Kraimer Date: 17MAR2000 */
#include <stddef.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <stdio.h>
#include "epicsExit.h"
#include "epicsThread.h"
#include "iocsh.h"
int main(int argc,char *argv[])
{
#ifdef iocshMain
return iocshMain(argc, argv);
#else
if(argc>=2) {
iocsh(argv[1]);
epicsThreadSleep(.2);
}
iocsh(NULL);
epicsExit(0);
return(0);
#endif
}
#ifdef __rtems__
__asm__(
".pushsection \".data\" \n"
".global _FSImageLocation \n"
"_FSImageLocation: \n"
".incbin \"image.tar\" \n"
".global _FSImageEnd \n"
"_FSImageEnd: \n"
".popsection \n"
);
#endif
- Replies:
- Re: rtems IMFS support/compatibility Siddons, David via Core-talk
- Re: rtems IMFS support/compatibility Gedare Bloom via Core-talk
- Navigate by Date:
- Prev:
Build failed in Jenkins: EPICS-3.14 #1062 Jenkins EPICS PSI via Core-talk
- Next:
Re: rtems IMFS support/compatibility Siddons, David via Core-talk
- Index:
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
<2021>
2022
2023
2024
- Navigate by Thread:
- Prev:
Build failed in Jenkins: EPICS-3.14 #1062 Jenkins EPICS PSI via Core-talk
- Next:
Re: rtems IMFS support/compatibility Siddons, David via Core-talk
- Index:
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
<2021>
2022
2023
2024