utils/reset: Remove fdt_reset_thead

In the past, we used fdt_reset_thead to help customers with prototype
verification. However, with the emergence of the Big-little SoC system,
it can no longer meet the demand. Therefore, we use zero_stage_boot
instead of fdt_reset_thead. It cleans up the opensbi code and ends the
disputation of reset_sample's dts.

This patch removes the fdt_reset_thead component and updates the related
doc.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>

1 files changed, 7 insertions, 176 deletions

diff --git a/docs/platform/thead-c9xx.md b/docs/platform/thead-c9xx.md
index 8bb9e91..cc05b58 100644
--- a/docs/platform/thead-c9xx.md
+++ b/docs/platform/thead-c9xx.md
@@ -1,7 +1,7 @@
 T-HEAD C9xx Series Processors
 =============================
 
-The **C9xx** series processors are high-performance RISC-V architecture
+The C9xx series processors are high-performance RISC-V architecture
 multi-core processors with AI vector acceleration engine.
 
 For more details, refer [T-HEAD.CN](https://www.t-head.cn/)
@@ -12,185 +12,16 @@ To build the platform-specific library and firmware images, provide the
 Platform Options
 ----------------
 
-The *T-HEAD C9xx* does not have any platform-specific compile options
+The T-HEAD C9xx does not have any platform-specific compile options
 because it uses generic platform.
 
 ```
-CROSS_COMPILE=riscv64-linux-gnu- PLATFORM=generic /usr/bin/make
+CROSS_COMPILE=riscv64-linux-gnu- PLATFORM=generic make
 ```
 
-The *T-HEAD C9xx* DTB provided to OpenSBI generic firmwares will usually have
-"riscv,clint0", "riscv,plic0", "thead,reset-sample" compatible strings.
+Here is the simplest boot flow for a fpga prototype:
 
-DTS Example1: (Single core, eg: Allwinner D1 - c906)
-----------------------------------------------------
+ (Jtag gdbinit) -> (zsb) -> (opensbi) -> (linux)
 
-```
-	cpus {
-		#address-cells = <1>;
-		#size-cells = <0>;
-		timebase-frequency = <3000000>;
-		cpu@0 {
-			device_type = "cpu";
-			reg = <0>;
-			status = "okay";
-			compatible = "riscv";
-			riscv,isa = "rv64imafdcv";
-			mmu-type = "riscv,sv39";
-			cpu0_intc: interrupt-controller {
-				#interrupt-cells = <1>;
-				compatible = "riscv,cpu-intc";
-				interrupt-controller;
-			};
-		};
-	};
-
-	soc {
-		#address-cells = <2>;
-		#size-cells = <2>;
-		compatible = "simple-bus";
-		ranges;
-
-		clint0: clint@14000000 {
-			compatible = "allwinner,sun20i-d1-clint";
-			interrupts-extended = <
-				&cpu0_intc  3 &cpu0_intc  7
-				>;
-			reg = <0x0 0x14000000 0x0 0x04000000>;
-		};
-
-		intc: interrupt-controller@10000000 {
-			#interrupt-cells = <1>;
-			compatible = "allwinner,sun20i-d1-plic",
-				     "thead,c900-plic";
-			interrupt-controller;
-			interrupts-extended = <
-				&cpu0_intc  0xffffffff &cpu0_intc  9
-				>;
-			reg = <0x0 0x10000000 0x0 0x04000000>;
-			reg-names = "control";
-			riscv,max-priority = <7>;
-			riscv,ndev = <200>;
-		};
-	}
-```
-
-DTS Example2: (Multi cores with soc reset-regs)
------------------------------------------------
-
-```
-	cpus {
-		#address-cells = <1>;
-		#size-cells = <0>;
-		timebase-frequency = <3000000>;
-		cpu@0 {
-			device_type = "cpu";
-			reg = <0>;
-			status = "okay";
-			compatible = "riscv";
-			riscv,isa = "rv64imafdc";
-			mmu-type = "riscv,sv39";
-			cpu0_intc: interrupt-controller {
-				#interrupt-cells = <1>;
-				compatible = "riscv,cpu-intc";
-				interrupt-controller;
-			};
-		};
-		cpu@1 {
-			device_type = "cpu";
-			reg = <1>;
-			status = "fail";
-			compatible = "riscv";
-			riscv,isa = "rv64imafdc";
-			mmu-type = "riscv,sv39";
-			cpu1_intc: interrupt-controller {
-				#interrupt-cells = <1>;
-				compatible = "riscv,cpu-intc";
-				interrupt-controller;
-			};
-		};
-		cpu@2 {
-			device_type = "cpu";
-			reg = <2>;
-			status = "fail";
-			compatible = "riscv";
-			riscv,isa = "rv64imafdc";
-			mmu-type = "riscv,sv39";
-			cpu2_intc: interrupt-controller {
-				#interrupt-cells = <1>;
-				compatible = "riscv,cpu-intc";
-				interrupt-controller;
-			};
-		};
-		cpu@3 {
-			device_type = "cpu";
-			reg = <3>;
-			status = "fail";
-			compatible = "riscv";
-			riscv,isa = "rv64imafdc";
-			mmu-type = "riscv,sv39";
-			cpu3_intc: interrupt-controller {
-				#interrupt-cells = <1>;
-				compatible = "riscv,cpu-intc";
-				interrupt-controller;
-			};
-		};
-	};
-
-	soc {
-		#address-cells = <2>;
-		#size-cells = <2>;
-		compatible = "simple-bus";
-		ranges;
-
-		reset: reset-sample {
-			compatible = "thead,reset-sample";
-			entry-reg = <0xff 0xff019050>;
-			entry-cnt = <4>;
-			control-reg = <0xff 0xff015004>;
-			control-val = <0x1c>;
-			csr-copy = <0x7f3 0x7c0 0x7c1 0x7c2 0x7c3 0x7c5 0x7cc>;
-		};
-
-		clint0: clint@ffdc000000 {
-			compatible = "riscv,clint0";
-			interrupts-extended = <
-				&cpu0_intc  3 &cpu0_intc  7
-				&cpu1_intc  3 &cpu1_intc  7
-				&cpu2_intc  3 &cpu2_intc  7
-				&cpu3_intc  3 &cpu3_intc  7
-				&cpu4_intc  3 &cpu4_intc  7
-				>;
-			reg = <0xff 0xdc000000 0x0 0x04000000>;
-		};
-
-		intc: interrupt-controller@ffd8000000 {
-			#interrupt-cells = <1>;
-			compatible = "thead,c900-plic";
-			interrupt-controller;
-			interrupts-extended = <
-				&cpu0_intc  0xffffffff &cpu0_intc  9
-				&cpu1_intc  0xffffffff &cpu1_intc  9
-				&cpu2_intc  0xffffffff &cpu2_intc  9
-				&cpu3_intc  0xffffffff &cpu3_intc  9
-				>;
-			reg = <0xff 0xd8000000 0x0 0x04000000>;
-			reg-names = "control";
-			riscv,max-priority = <7>;
-			riscv,ndev = <80>;
-		};
-	}
-```
-
-DTS Example2: (Multi cores with old reset csrs)
------------------------------------------------
-```
-	reset: reset-sample {
-		compatible = "thead,reset-sample";
-		using-csr-reset;
-		csr-copy = <0x7c0 0x7c1 0x7c2 0x7c3 0x7c5 0x7cc
-			    0x3b0 0x3b1 0x3b2 0x3b3
-			    0x3b4 0x3b5 0x3b6 0x3b7
-			    0x3a0>;
-	};
-```
+For more details, refer:
+ [zero stage boot](https://github.com/c-sky/zero_stage_boot)