This cross-posted from Freedos-user. > [...] The kernel does not correctly > allocate MCBs for its configuration and initialization program code. The > code that an application loaded by INSTALL= returns to via termination > (pointed to by Int22) is in free memory. > > [...] > > The interrupt 22h handler is at address 8F8Eh:AB67h (at least with the > supplied kernel binary, build 2038, from 2009-05-16, WATCOMC, FAT32, and > in my test environment) for the application loaded with INSTALL=. This > segmented address is at the linear address 9A447h (= segmented > 9A44h:0007h). The only visible allocation of the kernel (owner = 60h) > during this time is at segment 9DD8h (MCB at 9DD7h), and its size is 227h > paragraphs. (The next MCB is the one at 9FFFh.) > > The affected functions are DoInstall, InstallExec, and init_DosExec, > which > call down in that order. init_DosExec is in intr.asm, the others are in > config.c. init_DosExec calls Int21.4B, ie Int22 points to its code. All > of > these functions execute in unallocated memory, though most others in > config.c probably do too. In my tests, Bret's application didn't > overwrite > InstallExec and init_DosExec but that depends entirely on how much memory > the application uses. (DoInstall had been overwritten.) > > I tested this again with build 2039, from 2010-08-01, WATCOMC, FAT32, > which is the latest kernel binary on the FreeDOS mirrors. In this case, > Int22 is at 9016h:A098h (linear 9A1F8h) and the kernel allocation is at > 9DC9h. The SVN repo does not appear to contain changes that might affect > this problem. > > Please release a stable build as soon as you have fixed that bug!
I would provide a patch but I'm not familiar with the kernel's memory allocation and how the kernel is relocated. Regards, Christian ------------------------------------------------------------------------------ The Next 800 Companies to Lead America's Growth: New Video Whitepaper David G. Thomson, author of the best-selling book "Blueprint to a Billion" shares his insights and actions to help propel your business during the next growth cycle. Listen Now! http://p.sf.net/sfu/SAP-dev2dev _______________________________________________ Freedos-kernel mailing list Freedos-kernel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-kernel
