Ian Lance Taylor-3 wrote: > > "Jeffi Edward.J" <j.jeffi@xxxxxxxxxxx> writes: > >> I do copying of .data from LMA to VMA as follows: >> >> memcpy(__data_start, __code_end, (__data_end - __data_start)); > > How did you declare those symbols in your C program? > > >> Using --print-map option to linker, I generated map file of symbols. >> I found the LMA of .data section in map file. >> VMA of my .data is 0x3000000(as per above skeleton script). >> Assume my LMA is 0x2000000 (__code_end). >> I calculated the offset of that global variable with respect to LMA >> region. >> I found in my LMA region itself, the global variables are not loaded >> properly. i.e the global variable has the same junk value in LMA region. >> >> I found from map file that some additional section are generated in >> between >> .data and .sdata. >> .eh_frame, .jcr, .data.rel.local, .data.rel.ro.local, .data.rel. >> >> Are these sections needed? Is my LMA region corrupted my any other >> section? > > Those sections are needed. > > >> On seeing the map file, I found that many additional section >> .text._ZN6DArray***, .rela.text._ZN6DArray***, .rela.sdata.__ZTIS***, >> .rela.rodata.__ZTIS***. > > Hmmm, C++. Do you see any .gnu.linkonce sections? If not, that is > fine. If you do, you should mention them in your linker script. > > > Unfortunately, I don't know what is going on. If the map file shows > that the data sections are being handled properly, then you should not > see junk in the LMA space. I don't know what could cause that. > > Ian > > Hi, I declared those symbols as extern char __data_start[] , extern char __code_end[], like that. There is no gnu.linkonce section in the map file. I checked the symbols generated as part of .text._ZN6DArray***, .rela.text._ZN6DArray***. Those symbols are some c++ identifiers. I found while loading the image in debugger that all global variables are loaded into VMA address space, although I have specified LMA using AT > lma region. But LMA has corrupted values. Since I have written memcpy() to copy from LMA to VMA, its getting corrupted. I'm totally confused why global variables are loaded @ VMA space. Please tell me the reason. Thanks and regards, Jeffi -- View this message in context: http://old.nabble.com/Garbage-values-in-LMA-of-.data-section-tp27140436p27210977.html Sent from the gcc - Help mailing list archive at Nabble.com.
