The current drivers/framework.c is useless, as REGISTER_DRIVER() is a macro
that just directly calls the driver probe function. Every board file has to
reference each driver's probe function by name. This was just done to make room
for proper driver probing in the future, where we are now, so implement that.
Make drivers self-register at link time by emitting a struct driver into a
.uniloader_drivers section via DRIVER_REGISTER(). The linker brackets
the section with __drivers_start / __drivers_end symbols.
Boards describe their hardware as a static struct with the format
{ driver_name, plat_data, label }. Remove the drivers_init hook from
struct board_ops as it's no longer necessary.
The drivers probe will now be placed between early_init and splash.
The framework looks up each device's driver_name up in the
linker section and calls probe(plat_data). A failed probe is logged.
Do --whole-archive as well to convince the linker to not drop the drivers
in archived .o files that aren't called outside the archive.
Adopt all boards to use the framework.
All of the changes in this commit are co-dependent on each other, as we're
doing a large change to the ABI.
The toolchain emits several sections that have no meaning for a flat
binary bootloader:
.eh_frame DWARF unwind tables (we never unwind)
.note.gnu.property BTI/PAC ELF markers (lost at objcopy)
.note.gnu.build-id debug identity (lost at objcopy)
.comment compiler version string
.ARM.attributes ABI metadata
Gcc emits roughly 7-8 KB of .eh_frame by default for a build of this
size; the others are smaller but equally pointless. Just drop all of
them in the linker scripts.
Net effect on dreamlte_defconfig w/ empty embedded blobs:
61960 -> ~54000 bytes. Stonks.
The C runtime requires that uninitialized global variables are zero.
In a bare-metal environment, memory contents are undefined at startup
and the BSS section is not automatically cleared, so we must zero out
this entire section ourselves.
Without this, static variables contain garbage values, leading to
unpredictable behavior. For example, the simplefb driver uses a static
variable to track the current print position, which resulted in text
being drawn at random locations on the screen.
At some point building for arm32 was broken, because the assumption
of an assembly memcpy existing was made. It, however, did not exist
for arm32, only arm64, hence build failing. Avoid this.
With support for this board also come the following changes:
- rework blobs handling to get past the 0 size bug
- basic cpu "set up" in start.S
- assembly memcpy
- uart debugging
Introduce stack and bss memory regions, rename Start.S to start.S
This commit should allow jumping out of assembly code for certain
SoCs that had issues with SP like MTK and QCOM.
Signed-off-by: Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
This was an issue for other armv7 boards that have slightly different
addresses till now. This also allows to start working on relocation
in the near future for both armv7 and aarch64.
While we're at it, fix some mistakes here and there.
Signed-off-by: Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
arch: Implement ARM32 support
soc: Implement ARM32 support for MSM8916
board: Implement ARM32 support for Samsung Galaxy J5 2015
include: main: Revert built-in memcpy, rearrange and add support for writel
lib: simplefb: Make the clear screen function usable
Signed-off-by: Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>
Cc: Efim Girjeu <efimgirjeu@gmail.com>
