> On 11. Mar 2022, at 19:10, Glenn Washburn <developm...@efficientek.com> wrote: > > On Fri, 11 Mar 2022 00:35:57 +0100 > Daniel Kiper <daniel.ki...@oracle.com> wrote: > >> Latest GCC may complain in that way: >> >> commands/i386/pc/sendkey.c: In function ‘grub_sendkey_postboot’: >> commands/i386/pc/sendkey.c:223:21: error: writing 1 byte into a region of >> size 0 [-Werror=stringop-overflow=] >> 223 | *((char *) 0x41a) = 0x1e; >> | ~~~~~~~~~~~~~~~~~~^~~~~~ > > I'm curious why I'm not seeing this. It looks like the target was > i386-pc, correct? I'm guessing this is on GCC11. What compiler are you > using? Any extra CFLAGS? Anything else I might need to reproduce? > > Glenn
gcc 11 can report those, I have used workaround of assigning address to variable. It is interesting that volatile qualifier can pacify it too. Rgds, Toomas > >> >> The volatile keyword addition helps and additionally assures us the >> compiler will not optimize out fixed assignments. >> >> Signed-off-by: Daniel Kiper <daniel.ki...@oracle.com> >> --- >> grub-core/commands/i386/pc/sendkey.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/grub-core/commands/i386/pc/sendkey.c >> b/grub-core/commands/i386/pc/sendkey.c >> index 26d9acd3d..ab4bca9e9 100644 >> --- a/grub-core/commands/i386/pc/sendkey.c >> +++ b/grub-core/commands/i386/pc/sendkey.c >> @@ -220,8 +220,8 @@ grub_sendkey_postboot (void) >> >> *flags = oldflags; >> >> - *((char *) 0x41a) = 0x1e; >> - *((char *) 0x41c) = 0x1e; >> + *((volatile char *) 0x41a) = 0x1e; >> + *((volatile char *) 0x41c) = 0x1e; >> >> return GRUB_ERR_NONE; >> } >> @@ -236,8 +236,8 @@ grub_sendkey_preboot (int noret __attribute__ ((unused))) >> oldflags = *flags; >> >> /* Set the sendkey. */ >> - *((char *) 0x41a) = 0x1e; >> - *((char *) 0x41c) = keylen + 0x1e; >> + *((volatile char *) 0x41a) = 0x1e; >> + *((volatile char *) 0x41c) = keylen + 0x1e; >> grub_memcpy ((char *) 0x41e, sendkey, 0x20); >> >> /* Transform "any ctrl" to "right ctrl" flag. */ > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > https://lists.gnu.org/mailman/listinfo/grub-devel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
