The GRUB is failing to build with GCC-12 in many places like this:
In function 'init_cbfsdisk',
inlined from 'grub_mod_init' at ../../grub-core/fs/cbfs.c:391:3:
../../grub-core/fs/cbfs.c:345:7: error: array subscript 0 is outside array bounds of 'grub_uint32_t[0]' {aka 'unsigned int[]'} [-Werror=array-bounds]
345 | ptr = *(grub_uint32_t *) 0xfffffffc;
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is caused by GCC regression in 11/12 [1]. In a nut shell, the
warning is about detected invalid accesses at non-zero offsets to NULL
pointers. Since hardwired constant address is treated as NULL plus an
offset in the same underlying code, the warning is therefore triggered.
Instead of inserting #pragma all over the places where literal pointers
are accessed to avoid diagnosing array-bounds, we can try to borrow the
idea from Linux kernel that the absolute_pointer() macro [2][3] is used
to disconnect a pointer using literal address from it's original object,
hence GCC won't be able to make assumptions on the boundary while doing
pointer arithmetic. With that we can greatly reduce the code we have to
cover up by making initial literal pointer assignment to use the new
wrapper but not having to track everywhere literal pointers are
accessed. This also makes code looks cleaner.
Please note the grub_absolute_pointer() macro requires to be invoked in
a function as long as it is compound expression. Some global variables
with literal pointers has been changed to local ones in order to use
grub_absolute_pointer() to initialize it. The shuffling is basically done
in a selective and careful way that the variable's scope doesn't matter
being local or global, for example, the global variable must not get
modified at run time throughout. For the record, here's the list of
global variables got shuffled in this patch:
grub-core/commands/i386/pc/drivemap.c:int13slot
grub-core/term/i386/pc/console.c:bios_data_area
grub-core/term/ns8250.c:serial_hw_io_addr
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578
[2] https://elixir.bootlin.com/linux/v5.16.14/source/include/linux/compiler.h#L180
[3] https://elixir.bootlin.com/linux/v5.16.14/source/include/linux/compiler-gcc.h#L31
Signed-off-by: Michael Chang <mchang@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
* configure.ac: Rename yeeloong platform to loongson. All users updated.
* grub-core/Makefile.core.def (fwstart_fuloong): New image.
* grub-core/boot/mips/loongson/fuloong.S: New file.
* grub-core/boot/mips/loongson/fwstart.S: Wait for CS5536 to come up.
Explicitly init CS5536.
[FULOONG]: Don't use serial until CS5536 is available.
Set GPIO based on dumps.
(serial_hw_init) [FULOONG]: Handle CS5536 parts.
[FULOONG]: Handle GPIO and memory controller differences.
Parse machine type in $a2.
* grub-core/boot/mips/startup_raw.S: Determine and save the
architecture.
* grub-core/bus/cs5536.c (gpiodump): Move to fwstart.S.
(grub_cs5536_init_geode): Remove gpio part. Conditionalise DIVIL
init on architecture type.
* grub-core/kern/mips/loongson/init.c (grub_machine_init): Init
SIS315E. Don't init at_keyboard on fuloong.
(grub_halt): Support Fuloong.
* grub-core/kern/mips/startup.S [LOONGSON]: Save $s7.
* grub-core/loader/mips/linux.c (LOONGSON_MACHTYPE): Removed.
(loongson_machtypes): New array.
(grub_cmd_linux) [GRUB_MACHINE_MIPS_LOONGSON]: Pass the right machine
type.
* grub-core/term/ns8250.c (serial_get_divisor): New parameter port and
config. All users updated. Handle CS5536 serial.
* grub-core/term/serial.c (grub_serial_register): Conditionalise
default port on machine type. Register serial as inactive.
* grub-core/video/sis315pro.c: New file.
* include/grub/cs5536.h (GRUB_CS5536_MSR_MAILBOX_CONFIG_ENABLED): New
definition.
(GRUB_CS5536_MSR_MAILBOX_CONFIG): Likewise.
(GRUB_CS5536_MSR_DIVIL_LEG_IO_UART1_COM1): Likewise.
(GRUB_CS5536_MSR_DIVIL_LEG_IO_UART2_COM3): Likewise.
(GRUB_CS5536_MSR_DIVIL_UART1_CONF): Likewise.
(GRUB_CS5536_MSR_DIVIL_UART2_CONF): Likewise.
* include/grub/mips/loongson.h (GRUB_CPU_LOONGSON_SHUTDOWN_GPIO): Rename
to ...
(GRUB_CPU_YEELOONG_SHUTDOWN_GPIO): ... this.
* include/grub/mips/loongson/kernel.h (GRUB_ARCH_MACHINE_YEELOONG): New
definition.
(GRUB_ARCH_MACHINE_FULOONG): Likewise.
(grub_arch_machine): New extern var.
* include/grub/mips/loongson/serial.h
(GRUB_MACHINE_SERIAL_DIVISOR_115200): Renamed to ...
(GRUB_MACHINE_SERIAL_PORT0_DIVISOR_115200): ... this.
(GRUB_MACHINE_SERIAL_PORT): Renamed to ...
(GRUB_MACHINE_SERIAL_PORT0): ... this.
(GRUB_MACHINE_SERIAL_PORT2_DIVISOR_115200): New definition.
(GRUB_MACHINE_SERIAL_PORT1): Likewise.
(GRUB_MACHINE_SERIAL_PORT2): Likewise.
(GRUB_MACHINE_SERIAL_PORTS): Include ports 1 and 2.
* include/grub/term.h (grub_term_register_input_inactive): New inline
function.
(grub_term_register_output_inactive): Likewise.
* include/grub/video.h (grub_video_driver_id): New value
GRUB_VIDEO_DRIVER_SIS315PRO.
* util/grub-mkimage.c (image_target_desc): Rename name to dirname.
New field "names". All users updated.
New field value IMAGE_FULOONG_FLASH.
(generate_image): USe separate fwstart hashes for yeeloong and fuloong.
