Files
opensbi/lib/utils/reset/fdt_reset_thead_asm.S
Guo Ren 49e422c5ad lib: utils: reset: Add T-HEAD sample platform reset driver
This driver is for T-HEAD test chip, fpga. It could work with
all T-HEAD riscv processors: C9xx series.

example1: (Using io-regs for reset)
reset: reset-sample {
	compatible = "thead,reset-sample";
	plic-delegate = <0xff 0xd81ffffc>;
	entry-reg = <0xff 0xff019050>;
	entry-cnt = <4>;
	control-reg = <0xff 0xff015004>;
	control-val = <0x1c>;
	csr-copy = <0x7f3 0x7c0 0x7c1 0x7c2 0x7c3 0x7c5 0x7cc>;
};

example2: (Using csr-regs for reset)
reset: reset-sample {
	compatible = "thead,reset-sample";
	plic-delegate = <0xff 0xd81ffffc>;
	using-csr-reset;
	csr-copy = <0x7c0 0x7c1 0x7c2 0x7c3 0x7c5 0x7cc
		    0x3b0 0x3b1 0x3b2 0x3b3
		    0x3b4 0x3b5 0x3b6 0x3b7
		    0x3a0>;
};

example3: (Only delegate plic enable to S-mode)
reset: reset-sample {
	compatible = "thead,reset-sample";
	plic-delegate = <0xff 0xd81ffffc>;
};

After this patch, all T-HEAD c9xx would use platform/generic with fw_dynamic
as default:

CROSS_COMPILE=riscv64-linux-gnu- PLATFORM=generic FW_PIC=y /usr/bin/make

The platform/thead will be deprecated.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-04-22 15:13:53 +05:30

48 lines
771 B
ArmAsm

/*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <sbi/riscv_asm.h>
#include "fdt_reset_thead.h"
/*
* csrrs rd, csr, rs1
* |31 20|19 15|14 12|11 7|6 0|
* csr rs1 010 rd 1110011
*/
#define CSR_STUB addi x0, x0, 0
.option norvc
.align 3
.global __fdt_reset_thead_csrr
__fdt_reset_thead_csrr:
csrrs a0, 0, x0
ret
.align 3
.global __thead_pre_start_warm
__thead_pre_start_warm:
/*
* Clear L1 cache & BTB & BHT ...
*/
li t1, 0x70013
csrw 0x7c2, t1
fence rw,rw
lla t1, custom_csr
.global __reset_thead_csr_stub
__reset_thead_csr_stub:
.rept MAX_CUSTOM_CSR
REG_L t2, 8(t1)
CSR_STUB
addi t1, t1, 16
.endr
/*
* Clear L1 cache & BTB & BHT ...
*/
li t1, 0x70013
csrw 0x7c2, t1
fence rw,rw
j _start_warm