OpenSBI is compiled with -fPIE, which generally implies dynamic linking.
This causes the compiler to generate GOT references for global symbols
in order to support runtime symbol interposition. However, OpenSBI does
not actually perform dynamic linking, so the GOT indirection just adds
unnecessary overhead.
The GOT references can be avoided by declaring global symbols with
hidden visibility, thus making them local to this dynamic object and
non-interposable. GCC/Clang's -fvisibility parameter is insufficient for
this purpose when referencing objects from other translation units;
either __attribute__((visibility(...)) or the pragma is required. Use
the pragma since it is easier to apply to every symbol. Additionally
clean up the one GOT reference from inline assembly.
With this change, a firmware linked with LLD does not contain either a
GOT or a PLT, and a firmware linked with BFD ld contains only a GOT with
a single (unreferenced, legacy) _GLOBAL_OFFSET_TABLE_ entry.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
The serial driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. The generic fdt_serial_init() first
attempts to match the chosen stdout device, and upon failure matches the
first available serial device in the DT. It is a fatal error if no such
device is found. This matches the behavior of fdt_driver_init_one().
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This allows the compiler to generate significantly better code, because
it does not have to maintain either the loop counter or loop limit. Plus
there are half as many symbols to relocate. This also simplifies passing
carray arrays to helper functions.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
When used to read characters from the terminal (e.g., when the SBI
console is used via ecall from linux with `console=hvc0`), we must
acknowledge receipt of each character to "pop" it off the LiteUART
hardware queue, and allow the next character to be made available.
Fixes: 52af6e4b ("lib: utils: Add LiteX UART support")
Suggested-by: Dolu1990 <charles.papon.90@gmail.com>
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
If there are multiple dt nodes, the previous code only tries to match
the first one, which may lose initialization.
Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
When the dt node has a status property and the value is not ok or
okay, skip initializing serial.
Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
For some debuggers that do not implement SYSWRITEC and SYSREADC
operations, we have to use SYSWRITE and SYSREAD.
Instead of implementing semihosting_putc() using SYSWRITE, let us
simply remove semihosting_putc() because console_putc/console_puts
are now interchangeable.
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
For some debuggers that do not implement SYSWRITEC and SYSREADC
operations, we can use SYSWRITE and SYSREAD instead like the
implementation of semihosting_getc().
Signed-off-by: Chen Pei <cp0613@linux.alibaba.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
The added memory region should start from the base address.
Otherwise, the range will be shifted by reg_offset and not
able to merge consecutive NAPOT regions in the root domain,
resulting in wasted PMP entries.
Fixes: e8bc1621 ("lib: utils/serial: Add shared regions for
serial drivers")
Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
The serial driver regions used by OpenSBI should be marked as a shared
read-write regions between M-mode and SU-mode as those are accessed
by earlycon and the corresponding tty serial drivers running in 'S' mode.
When the smepmp extension is enabled, PMP entries for these shared regions
will get programmed.
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
A final check of all DT nodes does not necessarily find a match, so
SBI_ENODEV needs to be returned. Optimize removal of current_driver.
Signed-off-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
The Cadence driver does not use the RX byte status feature and hence can
be advertised to be compatible with cdns,uart-r1p8 as well.
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
We fix the following semihosting compile error observed using LLVM:
lib/utils/serial/semihosting.c:158:12: error: result of comparison of constant -1 with expression of type 'char' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
ret = ch > -1 ? ch : -1;
~~ ^ ~~
Fixes: 7f09fba86e ("lib: utils/serial: add semihosting support")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
We update system drivers makefile to use kconfig for enabling/disabling
drivers. To avoid compile errors, we also enable appropriate system
drivers for each platform.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
We update serial drivers makefile to use kconfig for enabling/disabling
drivers. To avoid compile errors, we also enable appropriate serial
drivers for each platform.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
RISC-V doesn't generate exceptions on divide-by-zero, but the result,
all bits set, is not likely what people expect either. In all cases
where we divide by baudrate there's a chance it's zero (when the DT
it came from is "bad"). To avoid difficult to debug situations, leave
baudrate dependent registers alone when baudrate is zero, as, also in
all cases, it appears we can skip initialization of those registers
and still [hopefully] have a functioning UART.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
While it doesn't look like there are any current cases of using
uninitialized data, let's zero all the UART data members to be
safe. Zero may not actually be better than a random number in
some cases, so all structure members should still be validated
before use, but at least zero is usually easier to debug than
some random stack garbage...
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
The age old version of Shakti UART was upgraded long back, but we missed
updating the driver in OpenSBI. The old version of UART is not supported
anymore, hence removed the inline comment which is also outdated now.
Signed-off-by: Prasanna T <ptprasanna@gmail.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Instead of having FDT serial driver list hard-coded in the C source,
we generate it using carray.sh at compile-time.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
reg-offset property is used for offset to apply to the mapbase
from the start of the registers in 8250 UART. In Linux kernel,
it has been handled in 8250 UART driver.
dt-bindings:
<linux>/Documentation/devicetree/bindings/serial/8250.yaml
Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Initial commit of the xlnx-uartlite device and FDT support. This was
tested by running OpenSBI on a modified QEMU virt machine using the
xlnx-uartlite for serial.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Previously, it was rounded down and that gives suboptimal results when
non-standard clock sources or baud rates are used.
Signed-off-by: Jakub Luzny <jakub.luzny@codasip.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Using "void *" in arithmetic causes errors with strict compiler settings:
"error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]"
Avoid these by calculating on "char *" where 1-byte data size is assumed.
Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Some of RISC-V emulators provide HTIF at fixed base address so for
such emulators users have to hard-code HTIF base address in the
linker script.
To address this problem, we let users optionally provide fixed HTIF
base address via platform support (or device tree).
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Add support for the UART provided by the LiteX SoC
framework (https://github.com/enjoy-digital/litex),
based on its FDT info (described in the Linux tree at
Documentation/devicetree/bindings/serial/litex,liteuart.yaml).
Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This simply adds an helper to get fdt address which is more explicit than
sbi_scratch_thishart_arg1_ptr.
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
The value of the /chosen/stdout-path devicetree property is used to
determine the UART used by openSBI. According to the devicetree
specification the value may contain a hyphen, e.g.
chosen {
stdout-path = "/serial@f00:115200";
};
If the character ':' is present, it terminates the path of the device.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We should try other FDT drivers when we see SBI_ENODEV returned
by cold_init() of FDT driver.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Synopsys DesignWare APB UART is seen on the StarFive JH7100 SoC.
Its programming interface is compatible with the existing 8250
UART driver. Simply add its compatible string to the driver makes
it work with the StarFive JH7100 SoC on a BeagleV board.
With this patch, the generic platform firmware can be used out of
the box on the BeagleV board.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
This patch adds support for the UART used by the NOEL-V processor.
Cobham Gaisler's NOEL-V RISC-V processor IP is available under GPL
and commercial license and is described in more detail at
https://www.gaisler.com/noelv.
Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Instead of having console_putc() and console_getc() callbacks in
platform operations, it will be much simpler for console driver to
directly register these operations as device to the sbi_console
implementation.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Fix uart_putc implementation.
Due to a bug in the IP, this went unnoticed.
Use macros instead of magic numbers to make the code
more readable.
Signed-off-by: Vijai Kumar K <vijai@behindbytes.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
C-Class is a member of the SHAKTI family of processors from Indian
Institute of Technology - Madras(IIT-M).
It is an extremely configurable and commercial-grade 5-stage in-order
core supporting the standard RV64GCSUN ISA extensions.
https://gitlab.com/shaktiproject/cores/c-class/blob/master/README.md
We add OpenSBI support for Shakti C-class SoC.
Signed-off-by: Vijai Kumar K <vijai@behindbytes.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
We extend fdt_find_match() implementation by adding node offset
parameter which represents the first node to match from.
The improved fdt_find_match() can be used to find multiple
match nodes.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We add simple serial framework which will select and use serial driver
based on details in FDT passed by previous booting stage.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This fixes various coding style issues found in the serial codes.
No functional changes.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
