On Wed, 18 Nov 2015, Robert H wrote: > 2015-11-17 Sergei Gavrikov wrote: > > On Mon, 16 Nov 2015, Robert H wrote:
[snip] > >> I would be very pleased to know more about how the mechanism to get > >> ecos symbols works in hal_tables.h > > > > Generally and particularly (objloader case) the table boundaries are > > known > > > > https://sourceware.org/viewvc/ecos/packages/services/objloader/current/src/objelf.c?view=markup#l62 > > > > Look up example, objelf.c:cyg_ldr_external_address(): > > > > https://sourceware.org/viewvc/ecos/packages/services/objloader/current/src/objelf.c?view=markup#l219 > I probably still don't get it by looking at the source code how > entry->handler gets filled with the address of the symbol_name in the > ecos image. > > cyg_ldr_external_address is for accessing the symbol table in that > section until the entry-pointer reached the cyg_ldr_table_end-pointer, > but to me that still doesn't explain how entry->handler gets filled by > the right address. Notice, that eCos table macros is a quite smart way to declare the arrays of some C structure and keep them in a special memory region. For your case the array's item (or "row" of the table) is C struct cyg_ldr_table_entry: https://sourceware.org/viewvc/ecos/packages/services/objloader/current/include/objelf.h?revision=1.7&view=markup#l133 Similar in plain C extern int bar(); extern int foo(); struct s { char *name; void *call; }; struct s table[] = { { "bar", bar }, {"foo", foo}, }; struct s *table_end = &table[sizeof table / sizeof table[0]]; struct s *entry = table; while(entry != table_end) { if(strcmp(entry->name, "foo") == 0) { return entry->call; } entry++; } Hope, that no magic anymore. Sergei -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
