Вече на п-п-р

Код: Выделить всё

# https://stackoverflow.com/questions/19419782/exit-c-text0x18-undefined-reference-to-exit-when-using-arm-none-eabi-gcc
arm-none-eabi-gcc dummy.c --specs=nosys.specs

Код: Выделить всё

gcc -g -c dummy.c
ld dummy.o --defsym something=0x100500
ld: warning: cannot find entry symbol _start; defaulting to 00000000004000b0
den73@deb8:~/gddb$ gdb a.out
GNU gdb (Debian 7.12-6) 7.12.0.20161007-git
Reading symbols from a.out...done.
(gdb) info symbol something
Cannot access memory at address 0x100500
(gdb) ^d

Код: Выделить всё

den73@deb8:~/gddb$ objcopy a.out --only-keep-debug a.debug
den73@deb8:~/gddb$ strip a.out
den73@deb8:~/gddb$ gdb a.out
Reading symbols from a.out...(no debugging symbols found)...done.
(gdb) symbol-file a.debug
Reading symbols from a.debug...done.
(gdb) info symbol something
Cannot access memory at address 0x100500

Код: Выделить всё

arm-none-eabi-ld dummy.c -g -c --specs=nosys.specs -o dummy.o
arm-none-eabi-ld dummy.o --defsym v2=0x8020
arm-none-eabi-ld: warning: cannot find entry symbol _start; defaulting to 0000000000008000
arm-none-eabi-objcopy a.out --only-keep-debug a.debug
# запукаем в другом окне QEMU с ядром ЯОС с -s -S
arm-none-eabi-gdb -tui --command=~/commands.gdb 
(gdb) symbol-file a.debug
(gdb) x &v2
0x8020:       0x0001b000

Код: Выделить всё

git clone https://github.com/TinyCC/tinycc
cd tinycc
./configure
make
make test
cd ..
echo '#include <stdio.h>
int main() {
 printf("Hi!\n");
}' > a.c
tinycc/tcc -Btinycc a.c -o a.o
./a.o