Drivers: Started OpenSBI driver

Just ecall wrapper for now

TODO: Build system changes are lazy and need to be figured out

TODO: Looks like kernel.cpp was indented with tabs, fix

kernel/arch/riscv/platform/allwinner-d1/meson.build

@@ -8,6 +8,7 @@ arch_sources += [
 elf = executable(
     'kernel.elf',
     arch_sources,
+    include_directories: includes,
     link_args: [
         '-Wl,-T,' + meson.current_source_dir() + '/platform.ld',
         '-static'

kernel/drivers/opensbi/include/opensbi.h

@@ -0,0 +1,62 @@
+#pragma once
+
+typedef unsigned long uintmax_t;
+
+namespace drivers {
+namespace opensbi {
+
+    // We use uintmax_t to make sure this works on 32 and 64 bit
+    // At least thats how I hope this works..
+    // TODO: Add assert() to make sure this is the case
+    struct sbiret_t {
+        uintmax_t error;
+        uintmax_t value;
+    };
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2,
+            uintmax_t a3,
+            uintmax_t a4,
+            uintmax_t a5);
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2,
+            uintmax_t a3,
+            uintmax_t a4);
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2,
+            uintmax_t a3);
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2);
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1);
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0);
+
+}  // End namespace opensbi
+}  // End namespace drivers

kernel/drivers/opensbi/meson.build

@@ -0,0 +1,9 @@
+kernel_sources += [
+    files(
+        'opensbi.cpp'
+    ),
+]
+
+kernel_includes += include_directories(
+    'include'
+)

kernel/drivers/opensbi/opensbi.cpp

@@ -0,0 +1,78 @@
+#include <cstdint>
+#include <opensbi.h>
+
+namespace drivers {
+namespace opensbi {
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2,
+            uintmax_t a3,
+            uintmax_t a4,
+            uintmax_t a5) {
+        register uintmax_t r_a7 asm("a7") = extension;
+        register uintmax_t r_a6 asm("a6") = function;
+        register uintmax_t r_a0 asm("a0") = a0;
+        register uintmax_t r_a1 asm("a1") = a1;
+        register uintmax_t r_a2 asm("a2") = a2;
+        register uintmax_t r_a3 asm("a3") = a3;
+        register uintmax_t r_a4 asm("a4") = a4;
+        register uintmax_t r_a5 asm("a5") = a5;
+        asm volatile("ecall" :  // Instruction
+                "=r"(r_a0), "=r"(r_a1) :  // Inputs
+                "r"(r_a7), "r"(r_a6),  // Outputs
+                "r"(r_a0), "r"(r_a1), "r"(r_a2),
+                "r"(r_a3), "r"(r_a4), "r"(r_a5));
+        return {.error = a0, .value = a1};
+    }
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2,
+            uintmax_t a3,
+            uintmax_t a4) {
+        return call(extension, function, a0, a1, a2, a3, a4, 0);
+    }
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2,
+            uintmax_t a3) {
+        return call(extension, function, a0, a1, a2, a3, 0, 0);
+    }
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1,
+            uintmax_t a2) {
+        return call(extension, function, a0, a1, a2, 0, 0, 0);
+    }
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0,
+            uintmax_t a1) {
+        return call(extension, function, a0, a1, 0, 0, 0, 0);
+    }
+
+    sbiret_t call(
+            uintmax_t extension,
+            uintmax_t function,
+            uintmax_t a0) {
+        return call(extension, function, a0, 0, 0, 0, 0, 0);
+    }
+
+}  // End namespace opensbi
+}  // End namespace drivers

kernel/kernel.cpp

@@ -1,6 +1,8 @@
 #include <stdarg.h>
 #include <inttypes.h>
 
+#include <opensbi.h>
+
 #define read_csr(csr) \
 	({ \
 		unsigned long __v; \
@@ -28,6 +30,7 @@
 
 typedef unsigned long sbi_word;
 
+/*
 void sbi_call1(int ext, int func, sbi_word arg0) {
 	register sbi_word rExt asm("a7") = ext;
 	register sbi_word rFunc asm("a6") = func;
@@ -47,13 +50,14 @@ void sbi_call2(int ext, int func, sbi_word arg0, sbi_word arg1) {
 	if(rArg0)
 		__builtin_trap();
 }
+*/
 
 void fmt(const char *f, ...) {
 	va_list va;
 	va_start(va, f);
 	while(*f) {
 		if(*f != '{') {
-			sbi_call1(1, 0, *(f++));
+            drivers::opensbi::call(1, 0, *(f++));
 			continue;
 		}
 		f++;
@@ -69,7 +73,7 @@ void fmt(const char *f, ...) {
 		for(int i = 0; i < 16; ++i) {
 			const char *digits = "0123456789abcdef";
 			int d = (v >> (60 - i * 4)) & 0xF;
-			sbi_call1(1, 0, digits[d]);
+            drivers::opensbi::call(1, 0, digits[d]);
 		}
 	}
 	va_end(va);
@@ -216,20 +220,20 @@ extern "C" void handle_isr(isr_frame_t *frame) {
 		}else if(code == 5) { // Timer interrupt.
 			//clear_csr_bits("sie", sie_s_timer);
 			unsigned long time = read_csr("time");
-			sbi_call1(0x54494D45, 0, time + 100000);
+            drivers::opensbi::call(0x54494D45, 0, time + 100000);
 			save_stack(switch_task, current_task);
 		}else{
 			fmt("it's an unhandled interrupt, code: {}\n", code);
 		}
 	}else{
 		if(code == 8) { // Syscall.
-			sbi_call1(1, 0, frame->a[0]);
+            drivers::opensbi::call(1, 0, frame->a[0]);
 		}else{
 			unsigned long sepc = read_csr("sepc");
 			fmt("it's an exception at {}\n", sepc);
 			const char *s = exception_strings[cause];
 			while(*s)
-				sbi_call1(1, 0, *(s++));
+				drivers::opensbi::call(1, 0, *(s++));
 			while(1)
 				;
 		}
@@ -279,17 +283,18 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
 	(void)hart;
 	(void)dtb;
 
-    //fmt("test\n");
+    fmt("test\n");
+
+    fmt("uintmax: {} bits\n", sizeof(uintmax_t) * 8);
+    fmt("HART: {}, DTB: {}\n", hart, dtb);
 
-    /*
     volatile uint32_t *cfg = (uint32_t *)0x2000060;
     volatile uint32_t *dat = (uint32_t *)0x2000070;
 
     *cfg = 0x10;
     *dat = 0xFF;
-    */
 
-    fmt("y");
+    while(1);
 
 	cli();
 
@@ -302,7 +307,7 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
 	set_csr_bits("sie", sie_s_software | sie_s_timer);
 
 	// Self-IPI.
-	sbi_call2(0x735049, 0, 1 << hart, 0);
+    drivers::opensbi::call(0x735049, 0, 1 << hart, 0);
 
 	sti();
 	cli();
@@ -335,17 +340,17 @@ extern "C" void kmain(unsigned long hart, void *dtb) {
 	s = "paging works!\n";
 	s += 512UL * 1024 * 1024 * 1024;
 	while(*s)
-		sbi_call1(1, 0, *(s++));
+		drivers::opensbi::call(1, 0, *(s++));
 
 	create_task(&task1, task1_main);
 	create_task(&task2, task2_main);
 
 	time = read_csr("time");
-	sbi_call1(0x54494D45, 0, time + 100000);
+    drivers::opensbi::call(0x54494D45, 0, time + 100000);
 
 	save_stack(switch_task, 0);
 
-	sbi_call1(8, 0, 0);
+    drivers::opensbi::call(8, 0, 0);
 
 	while(1);
 }

kernel/meson.build

@@ -4,5 +4,16 @@ kernel_sources = [
     )
 ]
 
+kernel_includes = [
+    include_directories('include')
+]
+
+subdir('drivers/opensbi')
+
+includes = [
+#   arch_includes,
+    kernel_includes
+]
+
 subdir('arch/' + arch)