did something idk

.gitignore

@@ -1,3 +1,4 @@
 compile_commands.json
 kernel.elf
+.cache/
 *.o

Makefile

@@ -2,7 +2,7 @@ TOOLCHAIN = riscv64-linux-gnu-
 QEMU=qemu-system-riscv64
 KERNEL = kernel.elf
 
-CFLAGS=-march=rv64i_zicsr_d -mabi=lp64d -Wall -Wextra -Werror -O2 -g -Iinclude
+CFLAGS=-march=rv64i_zicsr_d -mabi=lp64d -Wall -Wextra -Werror -O2 -Iinclude -g
 LDFLAGS=-T linker.ld --no-dynamic-linker -m elf64lriscv -static -nostdlib
 QEMUFLAGS=-nographic -serial mon:stdio --no-reboot
 

include/atomic_helpers.h

@@ -3,14 +3,14 @@
 
 #define csrr(reg)                                                                                       \
     ({                                                                                                  \
-        uintptr_t temp;                                                                                 \
+        long temp;                                                                                      \
         __asm__ volatile("csrr  %0, " #reg : "=r"(temp));                                               \
         temp;                                                                                           \
     })
 
 #define csrw(reg, val)                                                                                  \
     ({                                                                                                  \
-        uintptr_t temp = (uintptr_t)val;                                                                \
+        long temp = (long)val;                                                                          \
         __asm__ volatile("csrw " #reg ", %0" ::"r"(temp));                                              \
     })
 

include/sbi.h

@@ -0,0 +1,31 @@
+#ifndef SBI_H
+#define SBI_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define EID_DEBUG_CONSOLE 0x4442434E
+#define EID_TIMER 0x54494D45
+
+#define FID_CONSOLE_WRITE 0
+#define FID_SET_TIMER 0
+
+typedef struct {
+    long error;
+    long value;
+} sbiret;
+
+sbiret sbi_ecall6(
+    int fid, int eid, size_t arg0, size_t arg1, size_t arg2, size_t arg3, size_t arg4, size_t arg5);
+
+#define sbi_ecall5(fid, eid, a0, a1, a2, a3, a4) sbi_ecall6(fid, eid, a0, a1, a2, a3, a4, 0)
+#define sbi_ecall4(fid, eid, a0, a1, a2, a3) sbi_ecall5(fid, eid, a0, a1, a2, a3, 0)
+#define sbi_ecall3(fid, eid, a0, a1, a2) sbi_ecall4(fid, eid, a0, a1, a2, 0)
+#define sbi_ecall2(fid, eid, a0, a1) sbi_ecall3(fid, eid, a0, a1, 0)
+#define sbi_ecall1(fid, eid, a0) sbi_ecall2(fid, eid, a0, 0)
+#define sbi_ecall0(fid, eid) sbi_ecall1(fid, eid, 0)
+
+sbiret sbi_debug_console_write(const char* str, size_t len);
+sbiret sbi_set_timer(uint64_t stime_value);
+
+#endif

src/kernel.c

@@ -1,22 +1,16 @@
+#include "atomic_helpers.h"
+#include "sbi.h"
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
-#include "atomic_helpers.h"
-
-#define DEBUG_ECALL 0x4442434E
-
-typedef struct {
-    long error;
-    long value;
-} sbiret;
 
 void trap_handler();
 void trap_handler_wrapper() __attribute__((naked));
 
 void user_entry();
 
-unsigned long strlen(const char* str) {
+size_t strlen(const char* str) {
-    unsigned long len = 0;
+    size_t len = 0;
     while(str[len] != '\0') {
         len++;
     }
@@ -28,7 +22,7 @@ int main() {
     csrw(stvec, trap_handler_wrapper);
     csrw(sepc, user_entry);
 
-    unsigned long sstatus = csrr(sstatus);
+    size_t sstatus = csrr(sstatus);
     sstatus |= (1 << 5);
     csrw(sstatus, sstatus);
 
@@ -36,76 +30,17 @@ int main() {
 }
 
 void user_entry(void) {
-    while(1) {
+    sbi_set_timer(1000000);
-        __asm__ volatile("ecall");
+    while(1) { }
-        __asm__ volatile("unimp");
-    }
-}
-
-__attribute__((always_inline)) 
-inline sbiret sbi_ecall6(unsigned long number, unsigned long arg0, unsigned long arg1, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) {
-    sbiret ret;
-
-    __asm__ volatile("mv a7, %[number]\n"
-                     "li a6, 0\n"
-                     "mv a0, %[arg0]\n"
-                     "mv a1, %[arg1]\n"
-                     "mv a2, %[arg2]\n"
-                     "mv a3, %[arg3]\n"
-                     "mv a4, %[arg4]\n"
-                     "mv a5, %[arg5]\n"
-                     "ecall\n"
-                     "mv %[err], a0\n"
-                     "mv %[val], a1\n"
-        : [err] "=r"(ret.error), [val] "=r"(ret.value)
-        : [number] "r"(number), [arg0] "r"(arg0), [arg1] "r"(arg1),
-[arg2] "r"(arg2),[arg3] "r"(arg3), [arg4] "r"(arg4),[arg5] "r"(arg5)  
-        : "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7");
-
-    return ret;
-}
-
-__attribute__((always_inline)) 
-inline sbiret sbi_ecall5(unsigned long number, unsigned long arg0, unsigned long arg1, unsigned long arg2, unsigned long arg3, unsigned long arg4) {
-    return sbi_ecall6(number, arg0, arg1, arg2, arg3, arg4, 0);
-}
-
-__attribute__((always_inline)) 
-inline sbiret sbi_ecall4(unsigned long number, unsigned long arg0, unsigned long arg1, unsigned long arg2, unsigned long arg3) {
-    return sbi_ecall5(number, arg0, arg1, arg2, arg3, 0);
-}
-
-__attribute__((always_inline)) 
-inline sbiret sbi_ecall3(unsigned long number, unsigned long arg0, unsigned long arg1, unsigned long arg2) {
-    return sbi_ecall4(number, arg0, arg1, arg2, 0);
-}
-
-__attribute__((always_inline)) 
-inline sbiret sbi_ecall2(unsigned long number, unsigned long arg0, unsigned long arg1) {
-    return sbi_ecall3(number, arg0, arg1, 0);
-}
-
-__attribute__((always_inline))
-inline sbiret sbi_ecall1(unsigned long number, unsigned long arg0) {
-    return sbi_ecall2(number, arg0, 0);
-}
-
-__attribute__((always_inline)) 
-inline sbiret sbi_ecall0(unsigned long number) {
-    return sbi_ecall1(number, 0);
-}
-
-sbiret console_debug_write(const char* str, unsigned long len) {
-    return sbi_ecall2(DEBUG_ECALL, len, (unsigned long)str);
 }
 
 int puts(const char* str) {
     sbiret ret;
-    if((ret = console_debug_write(str, strlen(str))).error != 0) {
+    if((ret = sbi_debug_console_write(str, strlen(str))).error != 0) {
         return -1;
     }
-    
+
-    if((ret = console_debug_write("\n", 1)).error != 0) {
+    if((ret = sbi_debug_console_write("\n", 1)).error != 0) {
         return -1;
     }
     return 0;
@@ -117,9 +52,9 @@ void trap_handler_wrapper() {
 }
 
 void trap_handler(void) {
-    unsigned long sepc = csrr(sepc);
+    size_t sepc = csrr(sepc);
-    unsigned long scause = csrr(scause);
+    size_t scause = csrr(scause);
-    unsigned long sstatus = csrr(sstatus);
+    size_t sstatus = csrr(sstatus);
 
     if(scause == 8) {
         puts("hello world");
@@ -127,18 +62,18 @@ void trap_handler(void) {
         sepc += 4;
         csrw(sepc, sepc);
         goto exit;
-    }
-
-    if(((sstatus >> 8) & 1) == 0) {
-        sepc += 4;
-        puts("exception occured in usermode, skipping past");
-        csrw(sepc, sepc);
-        goto exit;
     } else {
-        puts("exception occured in supervisor mode, panic");
+        if(((sstatus >> 8) & 1) == 0) {
+            sepc += 4;
+            puts("exception occured in usermode, skipping past");
+            csrw(sepc, sepc);
+            goto exit;
+        } else {
+            puts("exception occured in supervisor mode, panic");
 
-        while(1) {
+            while(1) {
-            __asm__ volatile("wfi");
+                __asm__ volatile("wfi");
+            }
         }
     }
 

src/sbi.c

@@ -0,0 +1,27 @@
+#include "sbi.h"
+
+sbiret sbi_ecall6(
+    int fid, int eid, size_t arg0, size_t arg1, size_t arg2, size_t arg3, size_t arg4, size_t arg5) {
+    register size_t a0 __asm__("a0") = arg0;
+    register size_t a1 __asm__("a1") = arg1;
+    register size_t a2 __asm__("a2") = arg2;
+    register size_t a3 __asm__("a3") = arg3;
+    register size_t a4 __asm__("a4") = arg4;
+    register size_t a5 __asm__("a5") = arg5;
+    register size_t a6 __asm__("a6") = fid;
+    register size_t a7 __asm__("a7") = eid;
+
+    __asm__ volatile("ecall"
+        : "=r"(a0), "=r"(a1)
+        : "r"(a0), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5), "r"(a6), "r"(a7)
+        : "memory");
+    return (sbiret){ .error = a0, .value = a1 };
+}
+
+sbiret sbi_debug_console_write(const char* str, size_t len) {
+    return sbi_ecall2(FID_CONSOLE_WRITE, EID_DEBUG_CONSOLE, len, (size_t)str);
+}
+
+sbiret sbi_set_timer(uint64_t stime_value) {
+    return sbi_ecall1(FID_SET_TIMER, EID_TIMER, stime_value);
+}