basic types and memory operations

kernel.c

@@ -1,28 +1,46 @@
-typedef unsigned char uint8_t;
-typedef unsigned int uint32_t;
-typedef uint32_t size_t;
+#include "kernel.h"
+#include "common.h"
 
 extern char __bss[], __bss_end[], __stack_top[];
 
-void *memset(void *buf, char c, size_t n) {
-    uint8_t *p = (uint8_t *) buf;
-    while (n--)
-        *p++ = c;
-    return buf;
+struct sbiret sbi_call(long arg0, long arg1, long arg2, long arg3, long arg4,
+                       long arg5, long fid, long eid) {
+    register long a0 __asm__("a0") = arg0;
+    register long a1 __asm__("a1") = arg1;
+    register long a2 __asm__("a2") = arg2;
+    register long a3 __asm__("a3") = arg3;
+    register long a4 __asm__("a4") = arg4;
+    register long a5 __asm__("a5") = arg5;
+    register long a6 __asm__("a6") = fid;
+    register long 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 (struct sbiret){.error = a0, .value = a1};
+}
+
+void putchar(char ch) {
+    sbi_call(ch, 0, 0, 0, 0, 0, 0, 1 /* Console Putchar */);
 }
 
 void kernel_main(void) {
-    memset(__bss, 0, (size_t) __bss_end - (size_t) __bss);
-    
-    for (;;);
+    printf("\n\nHello %s\n", "RETARD!");
+    printf("60 + 9 = %d, %x\n", 60 + 9, 0x1234abcd);
+
+    for (;;) {
+        __asm__ __volatile__("wfi");
+    }
 }
 
 __attribute__((section(".text.boot")))
 __attribute__((naked))
 void boot(void) {
     __asm__ __volatile__(
-        "mv sp, %[stack_top]\n" // Set stacker point
-        "j kernel_main\n"       // Jump to the kernel function
+        "mv sp, %[stack_top]\n" // Set the stack pointer
+        "j kernel_main\n"       // Jump to the kernel main function
         :
         : [stack_top] "r" (__stack_top) // Pass the stack top address as %[stack_top]
     );