Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
534aaa1802
On Exynos5 the call is simply ignored by most variants of the
trustzone firmware. However, on some devices it instead causes the
device to hang, so let's avoid the call for the SoCs where it should
not be needed.
To see that the call is ignored, we can look into sboot/tzsw. On most
of the Exynos{4,5} devices the part of sboot/tzsw that seem to handle
the secure monitor calls is quite easy to recognise, the SMC number is
compared to known ones, and if equal it branches to the relevant
function. In assembly this looks something like:
;-- handle_smc:
0x00000514 650070e3 cmn r0, 0x65
0x00000518 0a00000a beq loc.smc_cmd_reg
0x0000051c 010070e3 cmn r0, 1
0x00000520 6c00000a beq loc.smc_cmd_init
0x00000524 020070e3 cmn r0, 2
0x00000528 6b00000a beq loc.smc_cmd_info
0x0000052c 030070e3 cmn r0, 3
0x00000530 6e00000a beq loc.smc_cmd_sleep
0x00000534 060070e3 cmn r0, 6
0x00000538 ae00000a beq loc.smc_cmd_save_state
0x0000053c 070070e3 cmn r0, 7
0x00000540 b400000a beq loc.smc_cmd_standby
0x00000544 2b01001a bne loc.smc_return_minus1
where above example is from exynos5420-arndale-octa. As can be seen
the case where r0 is 4 (i.e. SMC_CMD_CPU1BOOT) is not handled. The
annotations are taken from github.com/hsnaves/exynos5410-firmware,
where a large part of the exynos5410 trustzone firmware has been
reverse-engineered.
Signed-off-by: Henrik Grimler <henrik@grimler.se>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20220118185746.299832-3-henrik@grimler.se
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
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|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.