opensbi.git/firmware/fw_base.S, branch v0.8

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

firmware: fw_base: Introduce optional fw_platform_init()

2020-05-01T05:03:02Z

We add optional fw_platform_init() function which will allow platform specific code to update "struct sbi_platform platform" before it is used. The fw_platform_init() can be a regular C function so before callint it we: 1. zero-out BSS section 2. Setup temporary trap handler to catch bugs 3. Setup temporary stack pointer Signed-off-by: Anup Patel Reviewed-by: Atish Patra

firmware: fw_base: Remove CSR_MTVEC update check

2020-05-01T03:58:38Z

Remove unnecessary CSR_MTVEC read to reduce the openSBI CSR requirement. Mux are costly in FPGA. Allowing CSR_MTVEC to be write only is usefull for the FMax/Area of FPGA softcore. https://github.com/SpinalHDL/opensbi.git branch mtvec Signed-off-by: Charles Papon Reviewed-by: Atish Patra Reviewed-by: Anup Patel

lib: sbi_trap: Simplify sbi_trap_handler() API

2020-03-28T08:02:23Z

This patch simplify sbi_trap_handler() API as follows: 1. Remove current hartid local variable because sbi_trap_handler() itself does not need it. 2. Remove scratch parameter because none of the functions directly called by sbi_trap_handler() require it. Signed-off-by: Anup Patel Reviewed-by: Atish Patra

include: sbi_platform: Introduce HART index to HART id table

2020-03-19T04:00:01Z

A platform can have discontinuous and/or sparse HART ids so we cannot always assume a set of HARTs with continuous HART ids. This patch adds support for discontinuous and sparse HART ids by introducing HART index to HART id table. This table has platform hart_count entries and it maps HART index to HART id. The HART index to HART id table has only two restrictions: 1. HART index < sbi_platform hart_count 2. HART id < SBI_HARTMASK_MAX_BITS Example1: Let's say we have a platform with 2 HART ids 11 and 22, for such a a platform: hart_count = 2 hart_index2id[0] = 11 hart_index2id[1] = 22 Example2: Let's say we have a platform with 5 HARTs ids 0, 1, 2, 3, and 4 but out of these HART with id 0 is not usable so for such a platform: hart_count = 5 hart_index2id[0] = -1U hart_index2id[1] = 1 hart_index2id[2] = 2 hart_index2id[3] = 3 hart_index2id[4] = 4 OR hart_count = 4 hart_index2id[0] = 1 hart_index2id[1] = 2 hart_index2id[2] = 3 hart_index2id[3] = 4 With HART index to HART id table in place, the hart_disabled() callback is now redundant so we remove it as well. Signed-off-by: Anup Patel Reviewed-by: Bin Meng Reviewed-by: Atish Patra

firmware: fw_base: Optimize _hartid_to_scratch() implementation

2020-03-13T06:48:51Z

This patch optimizes _hartid_to_scratch() in following ways: 1. Use caller saved registers instead of callee saved registers so that we don't need to save/restore registers on stack 2. Remove second redundant mul instruction by re-arranging instructions Overall, we reduce 9 instructions in _hartid_to_scratch() implementation. Signed-off-by: Anup Patel Reviewed-by: Atish Patra Reviewed-by: Bin Meng

firmware: Fix placement of .align directives

2020-01-10T04:00:27Z

Move the .align directives after switching the section. We want to align the start of the current section, not the end of the previous section. This also obsoletes the misguided workaround of disabling relaxation. Signed-off-by: Andreas Schwab Reviewed-by: Anup Patel