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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>
2019-04-08riscv: add support for multi-hart systemsLukas Auer
On RISC-V, all harts boot independently. To be able to run on a multi-hart system, U-Boot must be extended with the functionality to manage all harts in the system. All harts entering U-Boot are registered in the available_harts mask stored in global data. A hart lottery system as used in the Linux kernel selects the hart U-Boot runs on. All other harts are halted. U-Boot can delegate functions to them using smp_call_function(). Every hart has a valid pointer to the global data structure and a 8KiB stack by default. The stack size is set with CONFIG_STACK_SIZE_SHIFT. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-04-08riscv: save hart ID in register tp instead of s0Lukas Auer
The hart ID passed by the previous boot stage is currently stored in register s0. If we divert the control flow inside a function, which is required as part of multi-hart support, the function epilog may not be called, clobbering register s0. Save the hart ID in the unallocatable register tp instead to protect the hart ID. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-04-08riscv: delay initialization of caches and debug UARTLukas Auer
Move the initialization of the caches and the debug UART until after board_init_f_init_reserve. This is in preparation for SMP support, where code prior to this point will be executed by all harts. This ensures that initialization will only be performed once on the main hart running U-Boot. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-02-27riscv: generic: Ensure that U-Boot runs within 4GB for 64bit systemsAnup Patel
On 64bit systems, the DRAM top can be easily beyond 4GB and U-Boot DMA mapping APIs will generate DMA addresses beyond 4GB. This breaks DMA programming in 32bit DMA capable devices (such as Cadence MACB ethernet). For example, If DRAM is more then 2GB on QEMU sifive_u machine then Cadence MACB ethernet stops working for U-Boot because it is a 32bit DMA capable device. To handle 32bit DMA capable devices on 64bit systems, we provide custom implementation of board_get_usable_ram_top() which ensures that usable ram top is not more then 4GB. This in-turn ensures that U-Boot always runs within 4GB hence DMA addresses generated by DMA mapping APIs will be within 4GB too. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-02-27riscv: Rename cpu/qemu to cpu/genericAnup Patel
The QEMU CPU support under arch/riscv is pretty much generic and works fine for SiFive Unleashed as well. In fact, there will be quite a few RISC-V SOCs for which QEMU CPU support will work fine. This patch renames cpu/qemu to cpu/generic to indicate the above fact. If there are SOC specific errata workarounds required in cpu/generic then those can be done at runtime in cpu/generic based on CPU vendor specific DT compatible string. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-01-15riscv: move the AX25-specific implementation of flush_dcache_allLukas Auer
The fence instruction is used to enforce device I/O and memory ordering constraints in RISC-V. It can not be relied on to directly affect the data cache on every CPU. Andes' AX25 does not have a coherence agent. Its fence instruction flushes the data cache and is used to keep data in the system coherent. The implementation of flush_dcache_all in lib/cache.c is therefore specific to the AX25. Move it into the AX25-specific cache.c in cpu/ax25/. This also adds a missing new line between flush_dcache_all and flush_dcache_range in lib/cache.c. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2018-12-18riscv: Save boot hart id to the global dataBin Meng
At present the hart id passed via a0 in the U-Boot entry is saved to s0 at the beginning but does not preserve later. Save it to the global data structure so that it can be used later. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Return to previous privilege level after trap handlingBin Meng
At present the trap handler returns to hardcoded M-mode/S-mode. Change to returning to previous privilege level instead. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Fix context restore before returning from trap handlerBin Meng
sp cannot be loaded before restoring other registers. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Move trap handler codes to mtrap.SBin Meng
Currently the M-mode trap handler codes are in start.S. For future extension, move them to a separate file mtrap.S. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Do some basic architecture level cpu initializationBin Meng
In arch_cpu_init_dm() do some basic architecture level cpu initialization, like FPU enable, etc. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Update supports_extension() to use desc from cpu driverBin Meng
This updates supports_extension() implementation to use the desc string from the cpu driver whenever possible, which avoids the reading of misa CSR for S-mode U-Boot. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Remove non-DM version of print_cpuinfo()Bin Meng
With DM CPU driver, the non-DM version of print_cpuinfo() is no longer needed. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: Probe cpus during bootBin Meng
This calls cpu_probe_all() to probe all available cpus. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: qemu: Add platform-specific Kconfig optionsBin Meng
Add the QEMU RISC-V platform-specific Kconfig options, to include CPU and timer drivers. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-18riscv: ax25: Hide the ax25-specific Kconfig optionBin Meng
There is no need to expose RISCV_NDS to the Kconfig menu as it is an ax25-specific option. Introduce a dedicated Kconfig option for the cache ops of ax25 platform and use that to guard the cache ops. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Rick Chen <rick@andestech.com>
2018-12-18riscv: qemu: Create a simple-bus driver for the soc nodeBin Meng
To enumerate devices on the /soc/ node, create a "simple-bus" driver to match "riscv-virtio-soc". Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Anup Patel <anup@brainfault.org>
2018-12-05riscv: ax25-ae350: Pass dtb address to u-boot with a1 registerRick Chen
ax25-ae350 use CONFIG_OF_BOARD via a2 and CONFIG_SYS_SDRAM_BASE to boot from ram which allow the board to override the fdt address originally. But after this patch riscv: save hart ID and device tree passed by prior boot stage It provide prior_stage_fdt_address which offer a temporary memory address to keep the dtb address passing from loader(gdb) to u-boot with a1. So passing via a2 and CONFIG_SYS_SDRAM_BASE is redundant and can be removed. And it also somehow may corrupted BBL if it was be arranged in CONFIG_SYS_SDRAM_BASE. In board_fdt_blob_setup() When boting from ram: prior_stage_fdt_address will be use to reserved dtb temporarily. When booting from ROM: dtb will be pre-burned in CONFIG_SYS_FDT_BASE, if it is flash base. Or CONFIG_SYS_FDT_BASE maybe a memory map space (NOT RAM or ROM) which is provided by HW. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com>
2018-12-05riscv: Add kconfig option to run U-Boot in S-modeAnup Patel
This patch adds kconfig option RISCV_SMODE to run U-Boot in S-mode. When this opition is enabled we use s<xyz> CSRs instead of m<xyz> CSRs. It is important to note that there is no equivalent S-mode CSR for misa and mhartid CSRs so we expect M-mode runtime firmware (BBL or equivalent) to emulate misa and mhartid CSR read. In-future, we will have more patches to avoid accessing misa and mhartid CSRs from S-mode. Signed-off-by: Anup Patel <anup@brainfault.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
2018-11-26riscv: cache: Implement i/dcache [status, enable, disable]Rick Chen
AndeStar RISC-V(V5) provide mcache_ctl register which can configure I/D cache as enabled or disabled. This CSR will be encapsulated by CONFIG_RISCV_NDS. If you want to configure cache on AndeStar V5 AE350 platform. YOu can enable [*] AndeStar V5 ISA support by make menuconfig. This approach also provide the expansion when the vender specific features are going to join in. Signed-off-by: Rick Chen <rick@andestech.com> Cc: Greentime Hu <greentime@andestech.com>
2018-11-26riscv: save hart ID and device tree passed by prior boot stageLukas Auer
Store the hart ID and device tree passed by the prior boot stage (in a0 and a1) in registers s0 and s1. Replace one use of s1 in start.S to avoid overwriting it. The device tree is also stored in memory to make it available to U-Boot with the configuration CONFIG_OF_PRIOR_STAGE. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2018-11-26riscv: do not blindly modify the mstatus CSRLukas Auer
The mstatus CSR includes WPRI (writes preserve values, reads ignore values) fields and must therefore not be set to zero without preserving these fields. It is not apparent why mstatus is set to zero here since it is not required for U-Boot to run. Remove it. This instruction and others encode zero as an immediate. RISC-V has the zero register for this purpose. Replace the immediates with the zero register. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
2018-11-26riscv: remove unused labels in start.SLukas Auer
The labels nmi_vector, trap_vector and handle_reset in start.S are not used for RISC-V. Remove them. Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>