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2020-08-25riscv: fu540: Use correct API to get L2 cache controller base addressBin Meng
At present fdtdec_get_addr() is used to get L2 cache controller base address. This only works for a fixed #address-cells and #size-cells. Change to use fdtdec_get_addr_size_auto_parent() instead. Signed-off-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Pragnesh Patel <pragnesh.patel@openfive.com>
2020-08-14riscv: sifive: fu540: redundant initializationHeinrich Schuchardt
We should not initialize a variable if the value is overwritten before being read. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Reviewed-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Pragnesh Patel <pragnesh.patel@sifive.com> Tested-by: Pragnesh Patel <pragnesh.patel@sifive.com> Reviewed-by: Rick Chen <rick@andestech.com>
2020-08-14riscv: sifive/fu540: kconfig: Move FU540 driver related options to the SoC levelBin Meng
All FU540 driver related options should be in the SoC level Kconfig. Signed-off-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Pragnesh Patel <pragnesh.patel@sifive.com> Tested-by: Pragnesh Patel <pragnesh.patel@sifive.com>
2020-08-14riscv: sifive/fu540: spl: Rename soc_spl_init()Bin Meng
spl_soc_init() seems to be a better name, as all SPL functions names start from the spl_ prefix. Signed-off-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Pragnesh Patel <pragnesh.patel@sifive.com> Tested-by: Pragnesh Patel <pragnesh.patel@sifive.com>
2020-07-24riscv: Fix linking error when building u-boot-spl with no SMP supportLeo Yu-Chi Liang
Switch off SMP support when building u-boot-spl would cause linking error as follow: undefined reference to 'secondary hart relocate' and 'smp_call_function'. Add macro to wrap up proper code region that needs SMP configuration on. Signed-off by: Leo Liang <ycliang@andestech.com> Cc: rick@andestech.com Reviewed-by: Bin Meng <bin.meng@windriver.com>
2020-07-24env: Enable SPI flash env for SiFive FU540Jagan Teki
SPI flash device on HiFive Unleashed has 32MiB Size. This patch adds SPI flash environment after U-Boot proper partition with a size of 128KiB. SPI flash partition layout(32MiB): 0 - 34 : reserved for GPT header 35 - 39 : unused 40 - 2087 : loader1 (SPL, FSBL) 2088 - 10279 : loader2 (U-Boot proper, U-Boot) 10280 - 10535 : environment 10536 - 65494 : rootfs 65528 - 65536 : distro script Note: the loader1 must start from 40th sector even though there are 6 free sectors prior since 40th sector is nearest flash sector boundary.  Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> Reviewed-by: Bin Meng <bin.meng@windriver.com> Tested-by: Bin Meng <bin.meng@windriver.com>
2020-07-24riscv: Make SiFive HiFive Unleashed board boot againBin Meng
Commit 40686c394e53 ("riscv: Clean up IPI initialization code") caused U-Boot failed to boot on SiFive HiFive Unleashed board. The codes inside arch_cpu_init_dm() may call U-Boot timer APIs before the call to riscv_init_ipi(). At that time the timer register base (e.g.: the SiFive CLINT device in this case) is unknown yet. It might be the name riscv_init_ipi() that misleads people to only consider it is related to IPI, but in fact the timer capability is provided by the same SiFive CLINT device that provides the IPI. Timer capability is needed for both UP and SMP. Considering that the original refactor does have benefits, that it makes the IPI code more similar to U-Boot initialization idioms. It also removes some quite ugly macros. Let's do the minimal revert instead of a complete revert, plus a fixes to arch_cpu_init_dm() to consider the SPL case. Fixes: 40686c394e53 ("riscv: Clean up IPI initialization code") Signed-off-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Sean Anderson <seanga2@gmail.com> Tested-by: Leo Liang <ycliang@andestech.com>
2020-07-06Merge branch 'next'Tom Rini
Merge all outstanding changes from the current next branch in now that we have released.
2020-07-03riscv: sifive: fu540: enable all cache ways from U-Boot properPragnesh Patel
Add L2 cache node to enable all cache ways from U-Boot proper. Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-01riscv: Add option to support RISC-V privileged spec 1.9Sean Anderson
Some older processors (notably the Kendryte K210) use an older version of the RISC-V privileged specification. The primary changes between the old and new are in virtual memory, and in the merging of three separate counter enable CSRs. Using the new CSR on an old processor causes an illegal instruction exception. This patch adds an option to use the old CSRs instead of the new one. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-01riscv: Clean up IPI initialization codeSean Anderson
The previous IPI code initialized the device whenever the first call was made to a riscv_*_ipi function. This made it difficult to determine when the IPI device was initialized. This patch introduces a new function riscv_init_ipi. It is called once during arch_cpu_init_dm. In SPL, it is called in spl_invoke_opensbi. Before this point, no riscv_*_ipi functions should be called. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2020-07-01riscv: Clear pending interrupts before enabling IPIsSean Anderson
On some platforms (k210), the previous stage bootloader may have not cleared pending IPIs before transferring control to U-Boot. This can cause race conditions, as multiple harts all attempt to initialize the IPI controller at once. This patch clears IPIs before enabling them, ensuring that only one hart modifies shared memory at once. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2020-06-04riscv: sifive: fu540: add SPL configurationPragnesh Patel
Add a support for SPL which will boot from L2 LIM (0x0800_0000) and then SPL will boot U-Boot FIT image (OpenSBI FW_DYNAMIC + u-boot.bin) from MMC boot devices. SPL related code is leveraged from FSBL (https://github.com/sifive/freedom-u540-c000-bootloader.git) Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> Tested-by: Jagan Teki <jagan@amarulasolutions.com>
2020-06-04riscv: cpu: fu540: Add support for cpu fu540Pragnesh Patel
Add SiFive fu540 cpu to support RISC-V arch Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> Tested-by: Jagan Teki <jagan@amarulasolutions.com>
2020-06-04riscv: Add _image_binary_end for SPLPragnesh Patel
For SPL_SEPARATE_BSS, Device tree will be put at _image_binary_end Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Jagan Teki <jagan@amarulasolutions.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Jagan Teki <jagan@amarulasolutions.com>
2020-05-18common: Drop linux/bitops.h from common headerSimon Glass
Move this uncommon header out of the common header. Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18common: Drop init.h from common headerSimon Glass
Move this uncommon header out of the common header. Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18common: Drop net.h from common headerSimon Glass
Move this header out of the common header. Network support is used in quite a few places but it still does not warrant blanket inclusion. Note that this net.h header itself has quite a lot in it. It could be split into the driver-mode support, functions, structures, checksumming, etc. Signed-off-by: Simon Glass <sjg@chromium.org>
2020-04-23riscv: Provide a mechanism to fix DT for reserved memoryAtish Patra
In RISC-V, M-mode software can reserve physical memory regions by setting appropriate physical memory protection (PMP) csr. As the PMP csr are accessible only in M-mode, S-mode U-Boot can not read this configuration directly. However, M-mode software can pass this information via reserved-memory node in device tree so that S-mode software can access this information. This patch provides a framework to copy to the reserved-memory node from one DT to another. This will be used to update the DT used by U-Boot and the DT passed to the next stage OS. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-04-23riscv: Introduce SPL_SMP Kconfig option for U-Boot SPLBin Meng
With SBI v0.2 HSM extension, only a single hart need to boot and enter operating system. The booting hart can bring up secondary harts one by one afterwards. For U-Boot running in SPL, SMP can be turned on, while in U-Boot proper, SMP can be optionally turned off if using SBI v0.2 HSM. Introduce a new SPL_SMP Kconfig option to support this. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-04-23riscv: Merge unnecessary SMP ifdefs in start.SBin Meng
Two consecutive SMP ifdefs blocks can be combined into one. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Atish Patra <atish.patra@wdc.com>
2020-04-23riscv: qemu: Remove the simple-bus driver for the SoC nodeBin Meng
Prior to QEMU v3.1.0, QEMU generated the 'virt' SoC node with a "riscv-virtio-soc" compatible string, and a "simple-bus" driver was created to accommodate that special case in U-Boot. Starting from QEMU v3.1.0, the SoC node was set as a "simple-bus", hence the special simple-bus driver is no longer needed. Update the doc to mention the latest tested QEMU version 4.2.0. Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2020-04-23riscv: ax25: cache: Remove SPL_RISCV_MMODE config checkPragnesh Patel
CONFIG_IS_ENABLED(FOO) will check FOO config option for U-Boot, SPL and TPL, so remove unnecessary CONFIG_IS_ENABLED() Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-02-10riscv: Remove unnecessary instructionSean Anderson
The add instruction on risc-v can have any three sources and targets, so there is no need for an intermediate mov. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-02-10riscv: Add option to print registers on exceptionSean Anderson
When debugging, it can be helpful to see more information about an unhandled exception. This patch adds an option to view the registers at the time of the trap, similar to the linux output on a kernel panic. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-02-10riscv: Fix breakage caused by linker relaxationSean Anderson
Due to the two-instruction sequence needed to access arbitrary memory locations, the RISC-V linker aggressively optimises memory accesses and jumps at link-time. This is called "linker relaxation," and is discussed in this SiFive article <https://www.sifive.com/blog/all-aboard-part-3-linker-relaxation-in-riscv-toolchain>. One of the optimizations in place is to assume that the __global_pointer symbol is placed in the gp register. To quote the article: "...The magic __global_pointer$ symbol is defined to point 0x800 bytes past the start of the .sdata section. The 0x800 magic number allows signed 12-bit offsets from __global_pointer$ to address symbols at the start of the .sdata section. The linker assumes that if this symbol is defined, then the gp register contains that value, which it can then use to relax accesses to global symbols within that 12-bit range. The compiler treats the gp register as a constant so it doesn't need to be saved or restored, which means it is generally only written by _start, the ELF entry point." However, U-Boot instead keeps the global data pointer in gp. This causes memory accesses and jumps optimized to use the gp pointer to fail. To fix this problem, we undefine the __global_pointer symbol. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2020-01-17common: Move relocate_code() to init.hSimon Glass
This is an init function so move it out of the common header. Avoid using the typedef so that we don't have to include the global_data header file. Also tidy up the function style in comments while we are here. Signed-off-by: Simon Glass <sjg@chromium.org>
2019-12-10riscv: add option to wait for ack from secondary harts in smp functionsLukas Auer
Add a wait option to smp_call_function() to wait for the secondary harts to acknowledge the call-function request. The request is considered to be acknowledged once each secondary hart has cleared the corresponding IPI. As part of the call-function request, the secondary harts invalidate the instruction cache after clearing the IPI. This adds a delay between acknowledgment (clear IPI) and fulfillment (call function) of the request. We want to use the acknowledgment to be able to judge when the request has been completed. Remove the delay by clearing the IPI after cache invalidation and just before calling the function from the request. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Rick Chen <rick@andestech.com> Tested-by: Rick Chen <rick@andestech.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-10riscv: Fix clear bss loop in the start-up codeRick Chen
For RV64, it will use sd instruction to clear t0 register, and the increament will be 8 bytes. So if the difference between__bss_strat and __bss_end was not 8 bytes aligned, the clear bss loop will overflow and acks like system hang. Signed-off-by: Rick Chen <rick@andestech.com> Cc: KC Lin <kclin@andestech.com> Cc: Alan Kao <alankao@andestech.com>
2019-12-10riscv: ax25: cache: Add SPL_RISCV_MMODE for SPLRick Chen
The mcache_ctl csr only can be manipulated in M mode. Add SPL_RISCV_MMODE for U-Boot SPL to control cache operation. Signed-off-by: Rick Chen <rick@andestech.com> Cc: KC Lin <kclin@andestech.com> Cc: Alan Kao <alankao@andestech.com>
2019-12-10riscv: ax25: add SPL supportRick Chen
The U-Boot SPL will boot in M mode and load the FIT image which include OpenSBI and U-Boot proper images. After loading progress, it will jump to OpenSBI first and then U-Boot proper which will run in S mode. Also remove V5L2_CACHE due to U-Boot SPL code size consideration. Without this concern, it can be enable manually for performance. Signed-off-by: Rick Chen <rick@andestech.com> Cc: KC Lin <kclin@andestech.com> Cc: Alan Kao <alankao@andestech.com>
2019-12-02common: Move board_get_usable_ram_top() out of common.hSimon Glass
Move this function into init.h which seems to be designed for this sort of thing. Also update the header to declare struct global_data so that it can be included without global_data.h being needed. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Tom Rini <trini@konsulko.com>
2019-12-02common: Move enable/disable_interrupts out of common.hSimon Glass
Move these two functions into the irq_funcs.h header file. Also move interrupt_handler_t as this is used by the irq_install_handler() function. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Tom Rini <trini@konsulko.com>
2019-12-02common: Move ARM cache operations out of common.hSimon Glass
These functions are CPU-related and do not use driver model. Move them to cpu_func.h Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com> Reviewed-by: Tom Rini <trini@konsulko.com>
2019-12-02common: Move some cache and MMU functions out of common.hSimon Glass
These functions belong in cpu_func.h. Another option would be cache.h but that code uses driver model and we have not moved these cache functions to use driver model. Since they are CPU-related it seems reasonable to put them here. Move them over. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Tom Rini <trini@konsulko.com>
2019-09-03riscv: cache: use CCTL to flush d-cacheRick Chen
Use CCTL command to do d-cache write back and invalidate instead of fence. Signed-off-by: Rick Chen <rick@andestech.com> Cc: KC Lin <kclin@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-09-03riscv: cache: Flush L2 cache before jump to linuxRick Chen
Flush and disable L2 cache in dcache_disable() which will be called in cleanup_before_linux() before jump to linux. The sequence will be preferred as below: L1 flush -> L1 disable -> L2 flush -> L2 disable Signed-off-by: Rick Chen <rick@andestech.com> Cc: KC Lin <kclin@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-09-03riscv: ax25: add imply v5l2 cache controllerRick Chen
Select the v5l2 UCLASS_CACHE driver for ax25. Signed-off-by: Rick Chen <rick@andestech.com> Cc: KC Lin <kclin@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-09-03riscv: update fix_rela_dynMarcus Comstedt
The addend is now added for RELOC_TYPE relocs. Also, changed the loop structure so that all the R_RISCV_RELATIVE relocs are not required to be at the beginning of the list. Signed-off-by: Marcus Comstedt <marcus@mc.pp.se> Cc: Rick Chen <rick@andestech.com>
2019-08-26riscv: support SPL stack and global data relocationLukas Auer
To support relocation of the stack and global data on RISC-V, the secondary harts must be notified of the change using IPIs. We can reuse the hart relocation code for this purpose. It uses global data to store the new stack pointer and global data pointer for the secondary harts. This means that we cannot update the global data pointer of the main hart in spl_relocate_stack_gd(), because the secondary harts have not yet been relocated at this point. It is updated after the secondary harts have been notified. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-26riscv: add SPL supportLukas Auer
U-Boot SPL on the generic RISC-V CPU supports two boot flows, directly jumping to the image and via OpenSBI firmware. In the first case, both U-Boot SPL and proper must be compiled to run in the same privilege mode. Using OpenSBI firmware, U-Boot SPL must be compiled for machine mode and U-Boot proper for supervisor mode. To be able to use SPL, boards have to provide a supported SPL boot device. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-26riscv: add run mode configuration for SPLLukas Auer
U-Boot SPL can be run in a different privilege mode from U-Boot proper. Add new configuration entries for SPL to allow the run mode to be configured independently of U-Boot proper. Extend all uses of the CONFIG_RISCV_SMODE and CONFIG_RISCV_MMODE configuration symbols to also cover the SPL equivalents. Ensure that files compatible with only one privilege mode are not included in builds targeting an incompatible privilege mode. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-15riscv: Access CSRs using CSR numbersBin Meng
We should prefer accessing CSRs using their CSR numbers because: 1. It compiles fine with older toolchains. 2. We can use latest CSR names in #define macro names of CSR numbers as-per RISC-V spec. 3. We can access newly added CSRs even if toolchain does not recognize newly added CSRs by name. This commit is inspired from Linux kernel commit a3182c91ef4e ("RISC-V: Access CSRs using CSR numbers"). Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2019-05-18CONFIG_SPL_SYS_[DI]CACHE_OFF: addTrevor Woerner
While converting CONFIG_SYS_[DI]CACHE_OFF to Kconfig, there are instances where these configuration items are conditional on SPL. This commit adds SPL variants of these configuration items, uses CONFIG_IS_ENABLED(), and updates the configurations as required. Acked-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Trevor Woerner <trevor@toganlabs.com> [trini: Make the default depend on the setting for full U-Boot, update more zynq hardware] Signed-off-by: Tom Rini <trini@konsulko.com>
2019-05-09riscv: prior_stage_fdt_address should only be used when OF_PRIOR_STAGE is ↵Rick Chen
enabled This patch will fix prior_stage_fdt_address write failure problem, when AE350 boots from flash. When AE350 boots from flash, prior_stage_fdt_address will be flash address, we shall avoid it to be written. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2019-05-09riscv: Introduce CONFIG_XIP to support booting from flashRick Chen
When U-Boot boots from flash, during the boot process, hart_lottery and available_harts_lock variable addresses point to flash which is not writable. This causes boot failures on AE350. Introduce a config option CONFIG_XIP to support such configuration. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-04-08riscv: ax25: Andes specific cache shall only support in M-modeRick Chen
Limit the cache configuration only can be supported in M mode. It can not be manipulated in S mode. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2019-04-08riscv: ax25: Add platform-specific Kconfig optionsRick Chen
Add ax25 RISC-V platform-specific Kconfig options, to include CPU and timer drivers. Also disable ATCPIT100 SoC timer and replace by PLMT. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2019-04-08riscv: hang if relocation of secondary harts failsLukas Auer
Print an error message and hang if smp_call_function() returns an error, indicating that relocation of the secondary harts has failed. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-04-08riscv: do not rely on hart ID passed by previous boot stageLukas Auer
RISC-V U-Boot expects the hart ID to be passed to it via register a0 by the previous boot stage. Machine mode firmware such as BBL and OpenSBI do this when starting their payload (U-Boot) in supervisor mode. If U-Boot is running in machine mode, this task must be handled by the boot ROM. Explicitly populate register a0 with the hart ID from the mhartid CSR to avoid possible problems on RISC-V processors with a boot ROM that does not handle this task. Suggested-by: Rick Chen <rick@andestech.com> Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com> Tested-by: Rick Chen <rick@andestech.com>
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