opensbi.git/firmware, branch v0.9

lib: sbi: Introduce sbi_trap_exit() API

2021-01-07T04:23:17Z

We introduce sbi_trap_exit() API which can help non-firmware (i.e. generic or platform) code to force exit trap/interrupt handling and resume execution at context pointed by parameter "const struct sbi_trap_regs *regs". This new sbi_trap_exit() API will help Keystone Enclave project to resume execution of enclave from custom SBI call handler. Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: fw_base: Optimize trap handler for RV32 systems

2020-12-01T11:44:32Z

On RV32 systems, we have two CSRs for M-mode status (MSTATUS and MSTATUSH) when H-extension is implemented. This means we have to save/restore MSTATUSH for RV32 systems only when H-extension is implemented. The current _trap_handler() has extra instructions (roughly 10) for conditional save/restore of MSTATUSH CSR. These extra instructions in RV32 _trap_handler() can be avoided if we create separate low-level trap handler for RV32 systems having H-extension. This patch optimizes low-level trap handler for RV32 systems accordingly. Signed-off-by: Anup Patel Reviewed-by: Alistair Francis

firmware: Remove FW_PAYLOAD_FDT_PATH compile-time option

2020-10-18T04:59:59Z

The FW_PAYLOAD_FDT_PATH compile-time option is replaced by FW_FDT_PATH compile-time option which is more flexible and common across all OpenSBI firmwares. This patch removes FW_PAYLOAD_FDT_PATH and updates related documentation to use FW_FDT_PATH. Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: Add common FW_FDT_PATH compile-time option

2020-10-18T04:58:26Z

Currently, only FW_PAYLOAD has mechanism to embed external FDT using FW_PAYLOAD_FDT_PATH compile-time option. This patch adds a common FW_FDT_PATH compile-time option to embed external FDT for all OpenSBI firmwares (i.e FW_JUMP, FW_PAYLOAD, and FW_DYNAMIC). Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: fw_base: Improve exception stack setup in trap handler

2020-08-14T09:05:47Z

Currently, the low-level trap handler (i.e. _trap_handler()) uses branch instructions to conditionally setup exception stack based on which mode trap occured. This patch implements exception stack setup using xor instructions which is faster with same number of instructions due to lack of branch instructions. The new exception stack setup approach can be best described by the following pseudocode: Came_From_M_Mode = ((MSTATUS.MPP < PRV_M) ? 1 : 0) - 1; Exception_Stack = TP ^ (Came_From_M_Mode & (SP ^ TP)) Came_From_M_Mode = 0 ==> Exception_Stack = TP Came_From_M_Mode = -1 ==> Exception_Stack = SP Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: Remove FW_PAYLOAD_FDT and related documentation

2020-06-05T03:33:05Z

Now that no platform is using FW_PAYLOAD_FDT mechanism, we remove related code from Makefile and related documentation. Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: Allow fw_platform_init() to return updated FDT location

2020-06-05T03:32:34Z

Currently, the fw_platform_init() does not return anything but we can further improve by allowing fw_platform_init() to return updated FDT location. It is certainly not mandatory for fw_platform_init() to return a new location of FDT (or modify FDT). In fact, the fw_platform_init() can always return the original FDT location (i.e. 'arg1') unmodified. This new capability of fw_platform_init() will allow platforms to: 1. Have multiple built-in FDTs and select one 2. Modify FDT before using based on platform specific straps or OTP Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: fw_base: Don't OR forced FW_OPTIONS

2020-06-05T03:32:32Z

Currently, we are ORing FW_OPTIONS with the options passed by previous booting stage to fw_dynamic. This causes confusion because compiling fw_dynamic with FW_OPTIONS=0x2 does not force enable boot prints as the U-Boot SPL passes options=0x1 in fw_dyanmic_info. The best thing to do is always prefer FW_OPTIONS when available. This is intuitive for OpenSBI users and easy in debugging. Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: fw_base: Make builtin DTB available to fw_platform_init()

2020-06-05T03:32:30Z

Currently, fw_prev_arg1() is called after fw_platform_init() which caused builtin DTB to be not available to fw_platform_init(). To allow builtin DTB available to fw_platform_init(), we should call fw_save_info() and fw_prev_arg1() before fw_platform_init(). Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: Correct spelling mistakes

2020-05-18T05:12:29Z

Signed-off-by: Daniel Schaefer Reviewed-by: Anup Patel