The ability to read a character from the console constitutes an attack
vector into TF-A, as it gives attackers a means to inject arbitrary
data into TF-A. It is dangerous to keep that feature enabled if not
strictly necessary, especially in production firmware builds.
Thus, we need a way to disable this feature. Moreover, when it is
disabled, all related code should be eliminated from the firmware
binaries, such that no remnant/dead getc() code remains in memory,
which could otherwise be used as a gadget as part of a bigger security
attack.
This patch disables getc() feature by default. For legitimate getc()
use cases [1], it can be explicitly enabled by building TF-A with
ENABLE_CONSOLE_GETC=1.
The following changes are introduced when getc() is disabled:
- The multi-console framework no longer provides the console_getc()
function.
- If the console driver selected by the platform attempts to register
a getc() callback into the multi-console framework then TF-A will
now fail to build.
If registered through the assembly function finish_console_register():
- On AArch64, you'll get:
Error: undefined symbol CONSOLE_T_GETC used as an immediate value.
- On AArch32, you'll get:
Error: internal_relocation (type: OFFSET_IMM) not fixed up
If registered through the C function console_register(), this requires
populating a struct console with a getc field, which will trigger:
error: 'console_t' {aka 'struct console'} has no member named 'getc'
- All console drivers which previously registered a getc() callback
have been modified to do so only when ENABLE_CONSOLE_GETC=1.
[1] Example of such use cases would be:
- Firmware recovery: retrieving a golden BL2 image over the console in
order to repair a broken firmware on a bricked board.
- Factory CLI tool: Drive some soak tests through the console.
Discussed on TF-A mailing list here:
https://lists.trustedfirmware.org/archives/list/tf-a@lists.trustedfirmware.org/thread/YS7F6RCNTWBTEOBLAXIRTXWIOYINVRW7/
Change-Id: Icb412304cd23dbdd7662df7cf8992267b7975cc5
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
And from crash_console_flush.
We ignore the error information return by console_flush in _every_
place where we call it, and casting the return type to void does not
work around the MISRA violation that this causes. Instead, we collect
the error information from the driver (to avoid changing that API), and
don't return it to the caller.
Change-Id: I1e35afe01764d5c8f0efd04f8949d333ffb688c1
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>
Since now the generic console_t structure holds the UART base address as
well, let's use that generic location and drop the UART driver specific
data structure at all.
Change-Id: I5c2fe3b6a667acf80c808cfec4a64059a2c9c25f
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
On some platforms the UART might have already been initialised, for
instance by firmware running before TF-A or by a separate management
processor. In this case it would not be need to initialise it again
(doing so could create spurious characters). But more importantly this
saves us from knowing the right baudrate and the right base clock rate
for the UART. This can lead to more robust and versatile firmware builds.
Allow to skip the 16550 UART initialisation and baud rate divisor
programming, by interpreting an input clock rate of "0" to signify this
case. This will just skip the call to console_16550_core_init, but still
will register the console properly.
Users should just pass 0 as the second parameter, the baudrate (third
parameter) will then be ignored as well.
Fix copy & paste typos in comments for the console_16550_register()
function on the way.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Change-Id: I9f8fca5b358f878fac0f31dc411358fd160786ee
Rockchip re-uses the ti uart console driver and for aarch32 needs a
specific variant, so add it.
There are also aarch32 ti socs, so it may be useful for them as well
at some point.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Change-Id: I31ede7cc7b10347b3691cff051db2b985fd59e17
The old version of the macro is deprecated.
Commit cc5859ca19 ("Multi-console: Deprecate the
`finish_console_register` macro") provides more details.
Change-Id: I3d1cdf6496db7d8e6cfbb5804f508ff46ae7e67e
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
Enforce full include path for includes. Deprecate old paths.
The following folders inside include/lib have been left unchanged:
- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}
The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).
For example, this patch had to be created because two headers were
called the same way: e0ea0928d5 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3a2 ("drivers: add tzc380 support").
This problem was introduced in commit 4ecca33988 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.
Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.
Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
The `finish_console_register` macro is used by the multi console
framework to register the `console_t` driver callbacks. It relied
on weak references to the `ldr` instruction to populate 0 to the
callback in case the driver has not defined the appropriate
function. Use of `ldr` instruction to load absolute address to a
reference makes the binary position dependant. These instructions
should be replaced with adrp/adr instruction for position independant
executable(PIE). But adrp/adr instructions don't work well with weak
references as described in GNU ld bugzilla issue 22589.
This patch defines a new version of `finish_console_register` macro
which can spcify which driver callbacks are valid and deprecates the
old one. If any of the argument is not specified, then the macro
populates 0 for that callback. Hence the functionality of the previous
deprecated macro is preserved. The USE_FINISH_CONSOLE_REG_2 define
is used to select the new variant of the macro and will be removed
once the deprecated variant is removed.
All the upstream console drivers have been migrated to use the new
macro in this patch.
NOTE: Platforms be aware that the new variant of the
`finish_console_register` should be used and the old variant is
deprecated.
Change-Id: Ia6a67aaf2aa3ba93932992d683587bbd0ad25259
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
The comments with the prototypes of the register functions of the
console drivers are incorrect. The arguments are wrong. This patch fixes
them.
Change-Id: I38c4b481ee69e840780111c42f03c0752eb6315c
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
On TI platforms the UART is disabled by default and must be explicitly
enabled using the MDR1 register.
NOTE: The original definition of
http://www.ti.com/lit/ds/symlink/pc16550d.pdf has no MDR register, but
many TI SoCs implementing 16550 do have a quirky MDR register
implemented. So, this should be enabled with TI_16550_MDR_QUIRK
NOTE: In such implementation, the CSR register does not exist.
Signed-off-by: Benjamin Fair <b-fair@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Replace placeholder by actual implementation.
Change-Id: I0861b1ac5304b0d2d7c32d7d9a48bd985e258e92
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
This patch updates the TI 16550 console driver to support the new
console API. The driver will continue to support the old API as well by
checking the MULTI_CONSOLE_API compile-time flag.
Change-Id: I60a44b7ba3c35c74561824c04b8dbe3e3039324c
Signed-off-by: Julius Werner <jwerner@chromium.org>
To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.
NOTE: Files that have been imported by FreeBSD have not been modified.
[0]: https://spdx.org/
Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
This patch removes the code that touched UART_FCR, from
console_core_putc(). The check for whether transmit FIFO is
full is sufficient before writing to UART TX FIFO. In fact
setting UARTFCR_TXCLR immediately after a byte is written to
FIFO might even result in loss of that byte, if UART hasn't
sent that byte out yet.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
It is needed to add placeholders for this function because, as this is
not a `plat_xxx()` function, there aren't weak definitions of it in any
file.
If `console_flush()` is used and there isn't an implementation of
`console_core_flush()` in any file, the compilation will fail.
Change-Id: I50eb56d085c4c9fbc85d40c343e86af6412f3020
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
tbz check for RDR status is to check for a bit being zero.
Unfortunately, we are using a mask rather than the bit position.
Further as per http://www.ti.com/lit/ds/symlink/pc16550d.pdf (page 17),
LSR register bit 0 is Data ready status (RDR), not bit position 2.
Update the same to match the specification.
Reported-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
This patch moves the various assembly console drivers
into `aarch64` architecture specific folder. Stub files,
which include files from new location, are retained at the
original location for platform compatibility reasons.
Change-Id: I0069b6c1c0489ca47f5204d4e26e3bc3def533a8
This patch adds driver for the 16550 UART interface. The driver is exposed
as a console, which platforms can use to dump their boot/crash logs.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Sandrine Bailleux
Jimmy Brisson
Andre Przywara
Ambroise Vincent
Heiko Stuebner
Antonio Nino Diaz
Soby Mathew
Benjamin Fair
Julius Werner
dp-arm
Varun Wadekar
Nishanth Menon