Initial Commit

5 files changed, 179 insertions, 0 deletions

diff --git a/VexRiscvSocSoftware/projects/murax/wip/.vscode/launch.json b/VexRiscvSocSoftware/projects/murax/wip/.vscode/launch.json
new file mode 100644
index 0000000..ef5432a
--- /dev/null
+++ b/VexRiscvSocSoftware/projects/murax/wip/.vscode/launch.json
@@ -0,0 +1,33 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations":
+    [
+        {
+            "name": "riscv64-unknown-elf-gdb",
+            "type": "cppdbg",
+            "request": "launch",
+            "MIMode": "gdb",
+            "miDebuggerPath": "/opt/riscv/bin/riscv64-unknown-elf-gdb",
+            "miDebuggerServerAddress": "localhost:3333",
+            "stopAtEntry": true,
+            //"preLaunchTask": "make",
+            "preLaunchTask": null,
+            "program": "${workspaceFolder}/build/democ.elf",
+            "args": [],
+            "environment": [],
+            "cwd": "${workspaceRoot}/build",
+            "externalConsole": true,
+            "setupCommands":
+            [
+                {
+                    "description": "Enable pretty-printing for gdb",
+                    "text": "-enable-pretty-printing",
+                    "ignoreFailures": true
+                }
+            ]
+        }
+    ]
+}
\ No newline at end of file
diff --git a/VexRiscvSocSoftware/projects/murax/wip/makefile b/VexRiscvSocSoftware/projects/murax/wip/makefile
new file mode 100755
index 0000000..b49287c
--- /dev/null
+++ b/VexRiscvSocSoftware/projects/murax/wip/makefile
@@ -0,0 +1,14 @@
+PROJ_NAME=democ
+DEBUG=yes
+BENCH=no
+MULDIV=no
+
+SRCS = 	$(wildcard src/*.c) \
+		$(wildcard src/*.cpp)
+
+INC += -I../../../libs/
+INC += -I../libs/
+LDSCRIPT = ../libs/linker.ld
+
+include ../../../resources/gcc.mk
+include ../../../resources/subproject.mk
diff --git a/VexRiscvSocSoftware/projects/murax/wip/readme.md b/VexRiscvSocSoftware/projects/murax/wip/readme.md
new file mode 100644
index 0000000..14330c1
--- /dev/null
+++ b/VexRiscvSocSoftware/projects/murax/wip/readme.md
@@ -0,0 +1,10 @@
+# DemoC
+
+This demo was inpired by:
+
+https://jacobmossberg.se/posts/2018/08/11/run-c-program-bare-metal-on-arm-cortex-m3.html
+
+It demonstrates using C to program bare metal app running on RISCV architecture.
+
+Included is also launch.json, which can be used for debugging the app, from VSCode. To run/debug, program Murax to FPGA and connect JTAG with openocd.
+
diff --git a/VexRiscvSocSoftware/projects/murax/wip/src/crt.c b/VexRiscvSocSoftware/projects/murax/wip/src/crt.c
new file mode 100644
index 0000000..70e6c06
--- /dev/null
+++ b/VexRiscvSocSoftware/projects/murax/wip/src/crt.c
@@ -0,0 +1,64 @@
+/*
+Created by: roman3017
+Inspired by: https://jacobmossberg.se/posts/2018/08/11/run-c-program-bare-metal-on-arm-cortex-m3.html
+*/
+
+extern unsigned int __global_pointer$;
+extern unsigned int _stack_start;
+extern unsigned int _bss_start;
+extern unsigned int _bss_end;
+extern unsigned int _ctors_start;
+extern unsigned int _ctors_end;
+
+void crtStart();
+void irqCallback();
+void main();
+
+static void trapEntry();
+static void bssInit();
+static void ctorsInit();
+
+unsigned int * initVectors[2] __attribute__ ((section("vectors"))) = {
+  (unsigned int *) crtStart,    // code entry
+  (unsigned int *) trapEntry,   // trap entry
+};
+
+void crtStart()
+{
+  /* Initialize sp and gp registers */
+  asm volatile (
+    "la gp, %0\n\t"
+    "la sp, %1\n\t"
+    :: "i"(&__global_pointer$), "i"(&_stack_start)
+  );
+
+  bssInit();
+  ctorsInit();
+  main();
+  asm volatile("j .");
+}
+
+static void trapEntry()
+{
+  irqCallback();
+}
+
+static void bssInit()
+{
+  unsigned int * bss_start_p = &_bss_start; 
+  unsigned int * bss_end_p = &_bss_end;
+  while(bss_start_p != bss_end_p) {
+    *bss_start_p++ = 0;
+  }
+}
+
+static void ctorsInit()
+{
+  unsigned int * ctors_start_p = &_ctors_start;
+  unsigned int * ctors_end_p = &_ctors_end;
+  void(*ctor)(); 
+  while(ctors_start_p != ctors_end_p) {
+    ctor = (void *)*ctors_start_p++;
+    ctor();
+  }
+}
diff --git a/VexRiscvSocSoftware/projects/murax/wip/src/main.c b/VexRiscvSocSoftware/projects/murax/wip/src/main.c
new file mode 100755
index 0000000..2d92b76
--- /dev/null
+++ b/VexRiscvSocSoftware/projects/murax/wip/src/main.c
@@ -0,0 +1,58 @@
+#include <stdint.h>
+#include <murax.h>
+
+/* bss section */
+uint32_t a, b, c;
+
+/* ctor section */
+void __attribute__ ((constructor)) defaultConstructor() 
+{
+	c += 3;
+} 
+
+/* text section */
+void main()
+{
+	uint32_t result;
+
+	interruptCtrl_init(TIMER_INTERRUPT);
+	prescaler_init(TIMER_PRESCALER);
+	timer_init(TIMER_A);
+
+	TIMER_PRESCALER->LIMIT = 12000-1; //1 ms rate
+
+	TIMER_A->LIMIT = 1000-1;  //1 second rate
+	TIMER_A->CLEARS_TICKS = 0x00010002;
+
+	TIMER_INTERRUPT->PENDINGS = 0xF;
+	TIMER_INTERRUPT->MASKS = 0x1;
+
+	GPIO_A->OUTPUT_ENABLE = 0x000000FF;
+	GPIO_A->OUTPUT = 0x00000000;
+
+	UART->STATUS = 2; //Enable RX interrupts
+	UART->DATA = 'A';
+
+	result = 0;
+	a = 1, b = 2;
+	while(1){
+		result += a;
+		result += b + c;
+		for(uint32_t idx = 0;idx < 50000;idx++) asm volatile("");
+		GPIO_A->OUTPUT = (GPIO_A->OUTPUT & ~0x3F) | ((GPIO_A->OUTPUT + 1) & 0x3F);  //Counter on LED[5:0]
+	}
+}
+
+void irqCallback()
+{
+	if(TIMER_INTERRUPT->PENDINGS & 1){  //Timer A interrupt
+		GPIO_A->OUTPUT ^= 0x80; //Toogle led 7
+		TIMER_INTERRUPT->PENDINGS = 1;
+	}
+	while(UART->STATUS & (1 << 9)){ //UART RX interrupt
+		UART->DATA = (UART->DATA) & 0xFF;
+	}
+}
+
+
+