u-boot/arch/Kconfig

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config ARCH_MAP_SYSMEM
depends on SANDBOX
def_bool y
config CREATE_ARCH_SYMLINK
bool
config HAVE_ARCH_IOREMAP
bool
config SYS_CACHE_SHIFT_4
bool
config SYS_CACHE_SHIFT_5
bool
config SYS_CACHE_SHIFT_6
bool
config SYS_CACHE_SHIFT_7
bool
config SYS_CACHELINE_SIZE
int
default 128 if SYS_CACHE_SHIFT_7
default 64 if SYS_CACHE_SHIFT_6
default 32 if SYS_CACHE_SHIFT_5
default 16 if SYS_CACHE_SHIFT_4
# Fall-back for MIPS
default 32 if MIPS
linker_lists: Fix alignment issue The linker script uses alphabetic sorting to group the different linker lists together. Each group has its own struct and potentially its own alignment. But when the linker packs the structs together it cannot ensure that a linker list starts on the expected alignment boundary. For example, if the first list has a struct size of 8 and we place 3 of them in the image, that means that the next struct will start at offset 0x18 from the start of the linker_list section. If the next struct has a size of 16 then it will start at an 8-byte aligned offset, but not a 16-byte aligned offset. With sandbox on x86_64, a reference to a linker list item using ll_entry_get() can force alignment of that particular linker_list item, if it is in the same file as the linker_list item is declared. Consider this example, where struct driver is 0x80 bytes: ll_entry_declare(struct driver, fred, driver) ... void *p = ll_entry_get(struct driver, fred, driver) If these two lines of code are in the same file, then the entry is forced to be aligned at the 'struct driver' alignment, which is 16 bytes. If the second line of code is in a different file, then no action is taken, since the compiler cannot update the alignment of the linker_list item. In the first case, an 8-byte 'fill' region is added: .u_boot_list_2_driver_2_testbus_drv 0x0000000000270018 0x80 test/built-in.o 0x0000000000270018 _u_boot_list_2_driver_2_testbus_drv .u_boot_list_2_driver_2_testfdt1_drv 0x0000000000270098 0x80 test/built-in.o 0x0000000000270098 _u_boot_list_2_driver_2_testfdt1_drv *fill* 0x0000000000270118 0x8 .u_boot_list_2_driver_2_testfdt_drv 0x0000000000270120 0x80 test/built-in.o 0x0000000000270120 _u_boot_list_2_driver_2_testfdt_drv .u_boot_list_2_driver_2_testprobe_drv 0x00000000002701a0 0x80 test/built-in.o 0x00000000002701a0 _u_boot_list_2_driver_2_testprobe_drv With this, the linker_list no-longer works since items after testfdt1_drv are not at the expected address. Ideally we would have a way to tell gcc not to align structs in this way. It is not clear how we could do this, and in any case it would require us to adjust every struct used by the linker_list feature. One possible fix is to force each separate linker_list to start on the largest possible boundary that can be required by the compiler. However that does not seem to work on x86_64, which uses 16-byte alignment in this case but needs 32-byte alignment. So add a Kconfig option to handle this. Set the default value to 4 so as to avoid changing platforms that don't need it. Update the ll_entry_start() accordingly. Signed-off-by: Simon Glass <sjg@chromium.org>
2020-12-17 04:20:06 +00:00
config LINKER_LIST_ALIGN
int
default 32 if SANDBOX
default 8 if ARM64 || X86
default 4
help
Force the each linker list to be aligned to this boundary. This
is required if ll_entry_get() is used, since otherwise the linker
may add padding into the table, thus breaking it.
See linker_lists.rst for full details.
choice
prompt "Architecture select"
default SANDBOX
config ARC
bool "ARC architecture"
select ARC_TIMER
select CLK
select DM
select HAVE_PRIVATE_LIBGCC
select SUPPORT_OF_CONTROL
select SYS_CACHE_SHIFT_7
select TIMER
select SYS_BIG_ENDIAN if CPU_BIG_ENDIAN
select SYS_LITTLE_ENDIAN if !CPU_BIG_ENDIAN
config ARM
bool "ARM architecture"
select ARCH_SUPPORTS_LTO
select CREATE_ARCH_SYMLINK
select HAVE_PRIVATE_LIBGCC if !ARM64
select SUPPORT_ACPI
select SUPPORT_OF_CONTROL
config M68K
bool "M68000 architecture"
select HAVE_PRIVATE_LIBGCC
select USE_PRIVATE_LIBGCC
select NEEDS_MANUAL_RELOC
select SYS_BOOT_GET_CMDLINE
select SYS_BOOT_GET_KBD
select SYS_CACHE_SHIFT_4
select SUPPORT_OF_CONTROL
config MICROBLAZE
bool "MicroBlaze architecture"
select SUPPORT_OF_CONTROL
imply CMD_TIMER
imply SPL_REGMAP if SPL
imply SPL_TIMER if SPL
imply TIMER
imply XILINX_TIMER
config MIPS
bool "MIPS architecture"
select HAVE_ARCH_IOREMAP
select HAVE_PRIVATE_LIBGCC
select SUPPORT_OF_CONTROL
select SPL_SEPARATE_BSS if SPL
config NIOS2
bool "Nios II architecture"
select CPU
select DM
select DM_EVENT
select OF_CONTROL
select SUPPORT_OF_CONTROL
imply CMD_DM
config PPC
bool "PowerPC architecture"
select HAVE_PRIVATE_LIBGCC
select SUPPORT_OF_CONTROL
select SYS_BOOT_GET_CMDLINE
select SYS_BOOT_GET_KBD
config RISCV
bool "RISC-V architecture"
select CREATE_ARCH_SYMLINK
select SUPPORT_OF_CONTROL
select OF_CONTROL
select DM
select DM_EVENT
imply SPL_SEPARATE_BSS if SPL
imply DM_SERIAL
imply DM_MMC
imply DM_SPI
imply DM_SPI_FLASH
imply BLK
imply CLK
imply MTD
imply TIMER
imply CMD_DM
imply SPL_DM
imply SPL_OF_CONTROL
imply SPL_LIBCOMMON_SUPPORT
imply SPL_LIBGENERIC_SUPPORT
imply SPL_SERIAL
imply SPL_TIMER
config SANDBOX
bool "Sandbox"
select ARCH_SUPPORTS_LTO
select BOARD_LATE_INIT
select BZIP2
select CMD_POWEROFF
dm: select CONFIG_DM* options As mentioned in the previous commit, adding default values in each Kconfig causes problems because it does not co-exist with the "depends on" syntax. (Please note this is not a bug of Kconfig.) We should not do so unless we have a special reason. Actually, for CONFIG_DM*, we have no good reason to do so. Generally, CONFIG_DM is not a user-configurable option. Once we convert a driver into Driver Model, the board only works with Driver Model, i.e. CONFIG_DM must be always enabled for that board. So, using "select DM" is more suitable rather than allowing users to modify it. Another good thing is, Kconfig warns unmet dependencies for "select" syntax, so we easily notice bugs. Actually, CONFIG_DM and other related options have been added without consistency: some into arch/*/Kconfig, some into board/*/Kconfig, and some into configs/*_defconfig. This commit prefers "select" and cleans up the following issues. [1] Never use "CONFIG_DM=n" in defconfig files It is really rare to add "CONFIG_FOO=n" to disable CONFIG options. It is more common to use "# CONFIG_FOO is not set". But here, we do not even have to do it. Less than half of OMAP3 boards have been converted to Driver Model. Adding the default values to arch/arm/cpu/armv7/omap3/Kconfig is weird. Instead, add "select DM" only to appropriate boards, which eventually eliminates "CONFIG_DM=n", etc. [2] Delete redundant CONFIGs Sandbox sets CONFIG_DM in arch/sandbox/Kconfig and defines it again in configs/sandbox_defconfig. Likewise, OMAP3 sets CONFIG_DM arch/arm/cpu/armv7/omap3/Kconfig and defines it also in omap3_beagle_defconfig and devkit8000_defconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-03-31 03:47:53 +00:00
select DM
select DM_EVENT
select DM_FUZZING_ENGINE
select DM_GPIO
select DM_I2C
select DM_KEYBOARD
select DM_MMC
dm: select CONFIG_DM* options As mentioned in the previous commit, adding default values in each Kconfig causes problems because it does not co-exist with the "depends on" syntax. (Please note this is not a bug of Kconfig.) We should not do so unless we have a special reason. Actually, for CONFIG_DM*, we have no good reason to do so. Generally, CONFIG_DM is not a user-configurable option. Once we convert a driver into Driver Model, the board only works with Driver Model, i.e. CONFIG_DM must be always enabled for that board. So, using "select DM" is more suitable rather than allowing users to modify it. Another good thing is, Kconfig warns unmet dependencies for "select" syntax, so we easily notice bugs. Actually, CONFIG_DM and other related options have been added without consistency: some into arch/*/Kconfig, some into board/*/Kconfig, and some into configs/*_defconfig. This commit prefers "select" and cleans up the following issues. [1] Never use "CONFIG_DM=n" in defconfig files It is really rare to add "CONFIG_FOO=n" to disable CONFIG options. It is more common to use "# CONFIG_FOO is not set". But here, we do not even have to do it. Less than half of OMAP3 boards have been converted to Driver Model. Adding the default values to arch/arm/cpu/armv7/omap3/Kconfig is weird. Instead, add "select DM" only to appropriate boards, which eventually eliminates "CONFIG_DM=n", etc. [2] Delete redundant CONFIGs Sandbox sets CONFIG_DM in arch/sandbox/Kconfig and defines it again in configs/sandbox_defconfig. Likewise, OMAP3 sets CONFIG_DM arch/arm/cpu/armv7/omap3/Kconfig and defines it also in omap3_beagle_defconfig and devkit8000_defconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-03-31 03:47:53 +00:00
select DM_SERIAL
select DM_SPI
select DM_SPI_FLASH
select GZIP_COMPRESSED
select IO_TRACE
select LZO
select OF_BOARD_SETUP
select PCI_ENDPOINT
select SPI
select SUPPORT_OF_CONTROL
select SYSRESET_CMD_POWEROFF
select SYS_CACHE_SHIFT_4
select IRQ
select SUPPORT_EXTENSION_SCAN
select SUPPORT_ACPI
imply BITREVERSE
select BLOBLIST
imply LTO
imply CMD_DM
imply CMD_EXCEPTION
imply CMD_GETTIME
imply CMD_HASH
imply CMD_IO
imply CMD_IOTRACE
imply CMD_LZMADEC
imply CMD_SF
imply CMD_SF_TEST
imply CRC32_VERIFY
imply FAT_WRITE
imply FIRMWARE
imply FUZZING_ENGINE_SANDBOX
imply HASH_VERIFY
imply LZMA
imply TEE
imply AVB_VERIFY
imply LIBAVB
imply CMD_AVB
imply PARTITION_TYPE_GUID
imply SCP03
imply CMD_SCP03
imply UDP_FUNCTION_FASTBOOT
imply VIRTIO_MMIO
imply VIRTIO_PCI
imply VIRTIO_SANDBOX
imply VIRTIO_BLK
imply VIRTIO_NET
imply DM_SOUND
imply PCI_SANDBOX_EP
imply PCH
imply PHYLIB
imply DM_MDIO
imply DM_MDIO_MUX
imply ACPI_PMC
imply ACPI_PMC_SANDBOX
imply CMD_PMC
imply CMD_CLONE
imply SILENT_CONSOLE
imply BOOTARGS_SUBST
sandbox: Add a DSA sandbox driver and unit test The DSA sandbox driver is used for unit testing the DSA class code. It implements a simple 2 port switch plus 1 CPU port, and uses a very simple tag to identify the ports. The DSA sandbox device is connected via CPU port to a regular Ethernet sandbox device, called 'dsa-test-eth, managed by the existing eth sandbox driver. The 'dsa-test-eth' is not intended for testing the eth class code however, but it is used to emulate traffic through the 'lan0' and 'lan1' front pannel switch ports. To achieve this the dsa sandbox driver registers a tx handler for the 'dsa-test-eth' device. The switch ports, labeled as 'lan0' and 'lan1', are also registered as eth devices by the dsa class code this time. So pinging through these switch ports is as easy as: => setenv ethact lan0 => ping 1.2.3.5 Unit tests for the dsa class code were also added. The 'dsa_probe' test exercises most API functions from dsa.h. The 'dsa' unit test simply exercises ARP/ICMP traffic through the two switch ports, including tag injection and extraction, with the help of the dsa sandbox driver. I took care to minimize the impact on the existing eth unit tests, though some adjustments needed to be made with the addition of extra eth interfaces used by the dsa unit tests. The additional eth interfaces also require MAC addresses, these have been added to the sandbox default environment. Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com> Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com> Reviewed-by: Simon Glass <sjg@chromium.org> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Message-Id: <20210216224804.3355044-5-olteanv@gmail.com> Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
2021-03-14 12:14:57 +00:00
imply PHY_FIXED
imply DM_DSA
imply CMD_EXTENSION
imply KEYBOARD
imply PHYSMEM
imply GENERATE_ACPI_TABLE
imply BINMAN
config SH
bool "SuperH architecture"
select HAVE_PRIVATE_LIBGCC
select SUPPORT_OF_CONTROL
config X86
bool "x86 architecture"
select SUPPORT_SPL
select SUPPORT_TPL
select CREATE_ARCH_SYMLINK
dm: select CONFIG_DM* options As mentioned in the previous commit, adding default values in each Kconfig causes problems because it does not co-exist with the "depends on" syntax. (Please note this is not a bug of Kconfig.) We should not do so unless we have a special reason. Actually, for CONFIG_DM*, we have no good reason to do so. Generally, CONFIG_DM is not a user-configurable option. Once we convert a driver into Driver Model, the board only works with Driver Model, i.e. CONFIG_DM must be always enabled for that board. So, using "select DM" is more suitable rather than allowing users to modify it. Another good thing is, Kconfig warns unmet dependencies for "select" syntax, so we easily notice bugs. Actually, CONFIG_DM and other related options have been added without consistency: some into arch/*/Kconfig, some into board/*/Kconfig, and some into configs/*_defconfig. This commit prefers "select" and cleans up the following issues. [1] Never use "CONFIG_DM=n" in defconfig files It is really rare to add "CONFIG_FOO=n" to disable CONFIG options. It is more common to use "# CONFIG_FOO is not set". But here, we do not even have to do it. Less than half of OMAP3 boards have been converted to Driver Model. Adding the default values to arch/arm/cpu/armv7/omap3/Kconfig is weird. Instead, add "select DM" only to appropriate boards, which eventually eliminates "CONFIG_DM=n", etc. [2] Delete redundant CONFIGs Sandbox sets CONFIG_DM in arch/sandbox/Kconfig and defines it again in configs/sandbox_defconfig. Likewise, OMAP3 sets CONFIG_DM arch/arm/cpu/armv7/omap3/Kconfig and defines it also in omap3_beagle_defconfig and devkit8000_defconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-03-31 03:47:53 +00:00
select DM
select HAVE_ARCH_IOMAP
select HAVE_PRIVATE_LIBGCC
select OF_CONTROL
select PCI
select SUPPORT_ACPI
select SUPPORT_OF_CONTROL
select SYS_CACHE_SHIFT_6
select TIMER
select USE_PRIVATE_LIBGCC
select X86_TSC_TIMER
select IRQ
imply HAS_ROM if X86_RESET_VECTOR
imply BLK
imply CMD_DM
imply CMD_FPGA_LOADMK
imply CMD_GETTIME
imply CMD_IO
imply CMD_IRQ
imply CMD_PCI
imply CMD_SF
imply CMD_SF_TEST
imply CMD_ZBOOT
imply DM_GPIO
imply DM_KEYBOARD
imply DM_MMC
imply DM_RTC
imply DM_SCSI
imply DM_SERIAL
imply DM_SPI
imply DM_SPI_FLASH
imply DM_USB
imply VIDEO
imply SYSRESET
imply SPL_SYSRESET
imply SYSRESET_X86
imply USB_ETHER_ASIX
imply USB_ETHER_SMSC95XX
imply USB_HOST_ETHER
imply PCH
imply PHYSMEM
imply RTC_MC146818
imply ACPIGEN if !QEMU && !EFI_APP
imply SYSINFO if GENERATE_SMBIOS_TABLE
imply SYSINFO_SMBIOS if GENERATE_SMBIOS_TABLE
imply TIMESTAMP
# Thing to enable for when SPL/TPL are enabled: SPL
imply SPL_DM
imply SPL_OF_LIBFDT
imply SPL_DRIVERS_MISC
imply SPL_GPIO
imply SPL_PINCTRL
imply SPL_LIBCOMMON_SUPPORT
imply SPL_LIBGENERIC_SUPPORT
imply SPL_SERIAL
imply SPL_SPI_FLASH_SUPPORT
imply SPL_SPI
imply SPL_OF_CONTROL
imply SPL_TIMER
imply SPL_REGMAP
imply SPL_SYSCON
# TPL
imply TPL_DM
imply TPL_DRIVERS_MISC
imply TPL_GPIO
imply TPL_PINCTRL
imply TPL_LIBCOMMON_SUPPORT
imply TPL_LIBGENERIC_SUPPORT
imply TPL_SERIAL
imply TPL_OF_CONTROL
imply TPL_TIMER
imply TPL_REGMAP
imply TPL_SYSCON
config XTENSA
bool "Xtensa architecture"
select CREATE_ARCH_SYMLINK
select SUPPORT_OF_CONTROL
endchoice
config SYS_ARCH
string
help
This option should contain the architecture name to build the
appropriate arch/<CONFIG_SYS_ARCH> directory.
All the architectures should specify this option correctly.
config SYS_CPU
string
help
This option should contain the CPU name to build the correct
arch/<CONFIG_SYS_ARCH>/cpu/<CONFIG_SYS_CPU> directory.
This is optional. For those targets without the CPU directory,
leave this option empty.
config SYS_SOC
string
help
This option should contain the SoC name to build the directory
arch/<CONFIG_SYS_ARCH>/cpu/<CONFIG_SYS_CPU>/<CONFIG_SYS_SOC>.
This is optional. For those targets without the SoC directory,
leave this option empty.
config SYS_VENDOR
string
help
This option should contain the vendor name of the target board.
If it is set and
board/<CONFIG_SYS_VENDOR>/common/Makefile exists, the vendor common
directory is compiled.
If CONFIG_SYS_BOARD is also set, the sources under
board/<CONFIG_SYS_VENDOR>/<CONFIG_SYS_BOARD> directory are compiled.
This is optional. For those targets without the vendor directory,
leave this option empty.
config SYS_BOARD
string
help
This option should contain the name of the target board.
If it is set, either board/<CONFIG_SYS_VENDOR>/<CONFIG_SYS_BOARD>
or board/<CONFIG_SYS_BOARD> directory is compiled depending on
whether CONFIG_SYS_VENDOR is set or not.
This is optional. For those targets without the board directory,
leave this option empty.
config SYS_CONFIG_NAME
string
help
This option should contain the base name of board header file.
The header file include/configs/<CONFIG_SYS_CONFIG_NAME>.h
should be included from include/config.h.
arch: armv8: Provide a way to disable cache maintenance ops On AM654 SoC(arm64) which is IO coherent and has L3 Cache, cache maintenance operations being done to support non-coherent platforms causes issues. For example, here is how U-Boot prepares/handles a buffer to receive data from a device (DMA Write). This may vary slightly depending on the driver framework: Start DMA to write to destination buffer Wait for DMA to be done (dma_receive()/dma_memcpy()) Invalidate destination buffer (invalidate_dcache_range()) Read from destination buffer The invalidate after the DMA is needed in order to read latest data from memory that’s updated by DMA write. Also, in case random prefetch has pulled in buffer data during the “wait for DMA” before the DMA has written to it. This works well for non-coherent architectures. In case of coherent architecture with L3 cache, DMA write would directly update L3 cache contents (assuming cacheline is present in L3) without updating the DDR memory. So invalidate after “wait for DMA” in above sequence would discard latest data and read will cause stale data to be fetched from DDR. Therefore invalidate after “wait for DMA” is not always correct on coherent architecture. Therefore, provide a Kconfig option to disable cache maintenance ops on coherent architectures. This has added benefit of improving the performance of DMA transfers as we no longer need to invalidate/flush individual cache lines(especially for buffer thats several KBs in size). In order to facilitate use of same Kconfig across different architecture, I have added the symbol to top level arch/Kconfig file. Patch currently disables cache maintenance ops for arm64 only. flush_dcache_all() and invalidate_dcache_all() are exclusively used during enabling/disabling dcache and hence are not disabled. Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
2019-04-22 16:13:32 +00:00
config SYS_DISABLE_DCACHE_OPS
bool
help
This option disables dcache flush and dcache invalidation
operations. For example, on coherent systems where cache
operatios are not required, enable this option to avoid them.
Note that, its up to the individual architectures to implement
this functionality.
config SYS_IMMR
hex "Address for the Internal Memory-Mapped Registers (IMMR) window"
depends on PPC || FSL_LSCH2 || FSL_LSCH3 || ARCH_LS1021A
default 0xFF000000 if MPC8xx
default 0xF0000000 if ARCH_MPC8313
default 0xE0000000 if MPC83xx && !ARCH_MPC8313
default 0x01000000 if ARCH_LS1021A || FSL_LSCH2 || FSL_LSCH3
default 0xFFE00000 if ARCH_P1010 || ARCH_P1011 || ARCH_P1020 || \
ARCH_P1021 || ARCH_P1024 || ARCH_P1025 || \
ARCH_P2020
default SYS_CCSRBAR_DEFAULT
help
Address for the Internal Memory-Mapped Registers (IMMR) window used
to configure the features of many Freescale / NXP SoCs.
config MONITOR_IS_IN_RAM
bool "U-Boot is loaded in to RAM by a pre-loader"
depends on M68K || NIOS2
menu "Skipping low level initialization functions"
depends on ARM || MIPS || RISCV
config SKIP_LOWLEVEL_INIT
bool "Skip calls to certain low level initialization functions"
help
If enabled, then certain low level initializations (like setting up
the memory controller) are omitted and/or U-Boot does not relocate
itself into RAM.
Normally this variable MUST NOT be defined. The only exception is
when U-Boot is loaded (to RAM) by some other boot loader or by a
debugger which performs these initializations itself.
config SPL_SKIP_LOWLEVEL_INIT
bool "Skip calls to certain low level initialization functions in SPL"
depends on SPL
help
If enabled, then certain low level initializations (like setting up
the memory controller) are omitted and/or U-Boot does not relocate
itself into RAM.
Normally this variable MUST NOT be defined. The only exception is
when U-Boot is loaded (to RAM) by some other boot loader or by a
debugger which performs these initializations itself.
config TPL_SKIP_LOWLEVEL_INIT
bool "Skip calls to certain low level initialization functions in TPL"
depends on SPL && ARM
help
If enabled, then certain low level initializations (like setting up
the memory controller) are omitted and/or U-Boot does not relocate
itself into RAM.
Normally this variable MUST NOT be defined. The only exception is
when U-Boot is loaded (to RAM) by some other boot loader or by a
debugger which performs these initializations itself.
config SKIP_LOWLEVEL_INIT_ONLY
bool "Skip call to lowlevel_init during early boot ONLY"
depends on ARM
help
This allows just the call to lowlevel_init() to be skipped. The
normal CP15 init (such as enabling the instruction cache) is still
performed.
config SPL_SKIP_LOWLEVEL_INIT_ONLY
bool "Skip call to lowlevel_init during early SPL boot ONLY"
depends on SPL && ARM
help
This allows just the call to lowlevel_init() to be skipped. The
normal CP15 init (such as enabling the instruction cache) is still
performed.
config TPL_SKIP_LOWLEVEL_INIT_ONLY
bool "Skip call to lowlevel_init during early TPL boot ONLY"
depends on TPL && ARM
help
This allows just the call to lowlevel_init() to be skipped. The
normal CP15 init (such as enabling the instruction cache) is still
performed.
endmenu
config SYS_HAS_NONCACHED_MEMORY
bool "Enable reserving a non-cached memory area for drivers"
depends on (ARM || MIPS) && (RTL8169 || MEDIATEK_ETH)
help
This is useful for drivers that would otherwise require a lot of
explicit cache maintenance. For some drivers it's also impossible to
properly maintain the cache. For example if the regions that need to
be flushed are not a multiple of the cache-line size, *and* padding
cannot be allocated between the regions to align them (i.e. if the
HW requires a contiguous array of regions, and the size of each
region is not cache-aligned), then a flush of one region may result
in overwriting data that hardware has written to another region in
the same cache-line. This can happen for example in network drivers
where descriptors for buffers are typically smaller than the CPU
cache-line (e.g. 16 bytes vs. 32 or 64 bytes).
config SYS_NONCACHED_MEMORY
hex "Size in bytes of the non-cached memory area"
depends on SYS_HAS_NONCACHED_MEMORY
default 0x100000
help
Size of non-cached memory area. This area of memory will be typically
located right below the malloc() area and mapped uncached in the MMU.
source "arch/arc/Kconfig"
source "arch/arm/Kconfig"
source "arch/m68k/Kconfig"
source "arch/microblaze/Kconfig"
source "arch/mips/Kconfig"
source "arch/nios2/Kconfig"
source "arch/powerpc/Kconfig"
source "arch/sandbox/Kconfig"
source "arch/sh/Kconfig"
source "arch/x86/Kconfig"
source "arch/xtensa/Kconfig"
source "arch/riscv/Kconfig"
if ARM || M68K || PPC
source "arch/Kconfig.nxp"
endif
source "board/keymile/Kconfig"
if MIPS || MICROBLAZE
choice
prompt "Endianness selection"
help
Some MIPS boards can be configured for either little or big endian
byte order. These modes require different U-Boot images. In general there
is one preferred byteorder for a particular system but some systems are
just as commonly used in the one or the other endianness.
config SYS_BIG_ENDIAN
bool "Big endian"
depends on (SUPPORTS_BIG_ENDIAN && MIPS) || MICROBLAZE
config SYS_LITTLE_ENDIAN
bool "Little endian"
depends on (SUPPORTS_LITTLE_ENDIAN && MIPS) || MICROBLAZE
endchoice
endif