From 4d063538f0493916dc6263276c4c84f31446db41 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Sun, 26 Apr 2020 14:31:28 +0530 Subject: [PATCH] firmware: fw_base: Introduce optional fw_platform_init() 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.S | 41 +++++++++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/firmware/fw_base.S b/firmware/fw_base.S index 07edc74..5cb0dfa 100644 --- a/firmware/fw_base.S +++ b/firmware/fw_base.S @@ -160,6 +160,32 @@ _relocate_done: li ra, 0 call _reset_regs + /* Zero-out BSS */ + la s4, _bss_start + la s5, _bss_end +_bss_zero: + REG_S zero, (s4) + add s4, s4, __SIZEOF_POINTER__ + blt s4, s5, _bss_zero + + /* Setup temporary trap handler */ + la s4, _start_hang + csrw CSR_MTVEC, s4 + + /* Setup temporary stack */ + la s4, _fw_end + li s5, (SBI_SCRATCH_SIZE * 2) + add sp, s4, s5 + + /* + * Initialize platform + * Note: The a0 to a4 registers passed to the + * firmware are parameters to this function. + */ + MOV_5R s0, a0, s1, a1, s2, a2, s3, a3, s4, a4 + call fw_platform_init + MOV_5R a0, s0, a1, s1, a2, s2, a3, s3, a4, s4 + /* Allow main firmware to save info */ MOV_5R s0, a0, s1, a1, s2, a2, s3, a3, s4, a4 call fw_save_info @@ -245,14 +271,6 @@ _scratch_init: add t1, t1, t2 blt t1, s7, _scratch_init - /* Zero-out BSS */ - la a4, _bss_start - la a5, _bss_end -_bss_zero: - REG_S zero, (a4) - add a4, a4, __SIZEOF_POINTER__ - blt a4, a5, _bss_zero - /* Override pervious arg1 */ MOV_3R s0, a0, s1, a1, s2, a2 call fw_prev_arg1 @@ -456,6 +474,13 @@ _start_hang: .section .entry, "ax", %progbits .align 3 + .globl fw_platform_init + .weak fw_platform_init +fw_platform_init: + ret + + .section .entry, "ax", %progbits + .align 3 .globl _trap_handler _trap_handler: /* Swap TP and MSCRATCH */ -- 2.7.4