+// See LICENSE for license details.
+
#include <stdint.h>
#include <string.h>
#include <stdarg.h>
-#include <machine/syscall.h>
-#include "pcr.h"
+#include <stdio.h>
+#include <limits.h>
+#include "util.h"
-void exit(int code)
+#define SYS_write 64
+#define SYS_exit 93
+#define SYS_stats 1234
+
+#undef strcmp
+
+extern volatile uint64_t tohost;
+extern volatile uint64_t fromhost;
+
+static uintptr_t handle_frontend_syscall(uintptr_t which, uint64_t arg0, uint64_t arg1, uint64_t arg2)
{
- volatile uint64_t magic_mem[8] = {0};
- magic_mem[0] = SYS_exit;
- magic_mem[1] = code;
+ volatile uint64_t magic_mem[8] __attribute__((aligned(64)));
+ magic_mem[0] = which;
+ magic_mem[1] = arg0;
+ magic_mem[2] = arg1;
+ magic_mem[3] = arg2;
__sync_synchronize();
- mtpcr(PCR_TOHOST, (long)magic_mem);
- while(1);
+
+ tohost = (uintptr_t)magic_mem;
+ while (fromhost == 0)
+ ;
+ fromhost = 0;
+
+ __sync_synchronize();
+ return magic_mem[0];
+}
+
+#define NUM_COUNTERS 2
+static uintptr_t counters[NUM_COUNTERS];
+static char* counter_names[NUM_COUNTERS];
+
+static int handle_stats(int enable)
+{
+ int i = 0;
+#define READ_CTR(name) do { \
+ while (i >= NUM_COUNTERS) ; \
+ uintptr_t csr = read_csr(name); \
+ if (!enable) { csr -= counters[i]; counter_names[i] = #name; } \
+ counters[i++] = csr; \
+ } while (0)
+
+ READ_CTR(mcycle);
+ READ_CTR(minstret);
+
+#undef READ_CTR
+ return 0;
+}
+
+void __attribute__((noreturn)) tohost_exit(uintptr_t code)
+{
+ tohost = (code << 1) | 1;
+ while (1);
+}
+
+uintptr_t handle_trap(uintptr_t cause, uintptr_t epc, uintptr_t regs[32])
+{
+ if (cause != CAUSE_MACHINE_ECALL)
+ tohost_exit(1337);
+ else if (regs[17] == SYS_exit)
+ tohost_exit(regs[10]);
+ else if (regs[17] == SYS_stats)
+ regs[10] = handle_stats(regs[10]);
+ else
+ regs[10] = handle_frontend_syscall(regs[17], regs[10], regs[11], regs[12]);
+
+ return epc + ((*(unsigned short*)epc & 3) == 3 ? 4 : 2);
+}
+
+static uintptr_t syscall(uintptr_t num, uintptr_t arg0, uintptr_t arg1, uintptr_t arg2)
+{
+ register uintptr_t a7 asm("a7") = num;
+ register uintptr_t a0 asm("a0") = arg0;
+ register uintptr_t a1 asm("a1") = arg1;
+ register uintptr_t a2 asm("a2") = arg2;
+ asm volatile ("scall" : "+r"(a0) : "r"(a1), "r"(a2), "r"(a7));
+ return a0;
+}
+
+void exit(int code)
+{
+ syscall(SYS_exit, code, 0, 0);
+ while (1);
+}
+
+void setStats(int enable)
+{
+ syscall(SYS_stats, enable, 0, 0);
}
void printstr(const char* s)
{
- volatile uint64_t magic_mem[8] = {0};
- magic_mem[0] = SYS_write;
- magic_mem[1] = 1;
- magic_mem[2] = (unsigned long)s;
- magic_mem[3] = strlen(s);
- __sync_synchronize();
- mtpcr(PCR_TOHOST, (long)magic_mem);
- while(mtpcr(PCR_FROMHOST, 0) == 0);
+ syscall(SYS_write, 1, (uintptr_t)s, strlen(s));
+}
+
+void __attribute__((weak)) thread_entry(int cid, int nc)
+{
+ // multi-threaded programs override this function.
+ // for the case of single-threaded programs, only let core 0 proceed.
+ while (cid != 0);
+}
+
+int __attribute__((weak)) main(int argc, char** argv)
+{
+ // single-threaded programs override this function.
+ printstr("Implement main(), foo!\n");
+ return -1;
}
+static void init_tls()
+{
+ register void* thread_pointer asm("tp");
+ extern char _tls_data;
+ extern __thread char _tdata_begin, _tdata_end, _tbss_end;
+ size_t tdata_size = &_tdata_end - &_tdata_begin;
+ memcpy(thread_pointer, &_tls_data, tdata_size);
+ size_t tbss_size = &_tbss_end - &_tdata_end;
+ memset(thread_pointer + tdata_size, 0, tbss_size);
+}
+
+void _init(int cid, int nc)
+{
+ init_tls();
+ thread_entry(cid, nc);
+
+ // only single-threaded programs should ever get here.
+ int ret = main(0, 0);
+
+ char buf[NUM_COUNTERS * 32] __attribute__((aligned(64)));
+ char* pbuf = buf;
+ for (int i = 0; i < NUM_COUNTERS; i++)
+ if (counters[i])
+ pbuf += sprintf(pbuf, "%s = %d\n", counter_names[i], counters[i]);
+ if (pbuf != buf)
+ printstr(buf);
+
+ exit(ret);
+}
+
+#undef putchar
int putchar(int ch)
{
- static char buf[64];
- static int buflen = 0;
+ static __thread char buf[64] __attribute__((aligned(64)));
+ static __thread int buflen = 0;
- if(ch != -1)
- buf[buflen++] = ch;
+ buf[buflen++] = ch;
- if(ch == -1 || buflen == sizeof(buf))
+ if (ch == '\n' || buflen == sizeof(buf))
{
- volatile uint64_t magic_mem[8] = {0};
- magic_mem[0] = SYS_write;
- magic_mem[1] = 1;
- magic_mem[2] = (long)buf;
- magic_mem[3] = buflen;
- __sync_synchronize();
- mtpcr(PCR_TOHOST, (long)magic_mem);
- while(mtpcr(PCR_FROMHOST, 0) == 0);
-
+ syscall(SYS_write, 1, (uintptr_t)buf, buflen);
buflen = 0;
}
printstr(str);
}
-static void printnum(void (*putch)(int, void**), void **putdat,
- unsigned long long num, unsigned base, int width, int padc)
+static inline void printnum(void (*putch)(int, void**), void **putdat,
+ unsigned long long num, unsigned base, int width, int padc)
{
- if (num >= base)
- printnum(putch, putdat, num / base, base, width - 1, padc);
- else while (--width > 0)
+ unsigned digs[sizeof(num)*CHAR_BIT];
+ int pos = 0;
+
+ while (1)
+ {
+ digs[pos++] = num % base;
+ if (num < base)
+ break;
+ num /= base;
+ }
+
+ while (width-- > pos)
putch(padc, putdat);
- putch("0123456789abcdef"[num % base], putdat);
+ while (pos-- > 0)
+ putch(digs[pos] + (digs[pos] >= 10 ? 'a' - 10 : '0'), putdat);
}
static unsigned long long getuint(va_list *ap, int lflag)
return va_arg(*ap, int);
}
-void vprintfmt(void (*putch)(int, void**), void **putdat, const char *fmt, va_list ap)
+static void vprintfmt(void (*putch)(int, void**), void **putdat, const char *fmt, va_list ap)
{
register const char* p;
const char* last_fmt;
for (width -= strnlen(p, precision); width > 0; width--)
putch(padc, putdat);
for (; (ch = *p) != '\0' && (precision < 0 || --precision >= 0); width--) {
- if (altflag && (ch < ' ' || ch > '~'))
- putch('?', putdat);
- else
- putch(ch, putdat);
+ putch(ch, putdat);
p++;
}
for (; width > 0; width--)
num = -(long long) num;
}
base = 10;
- goto number;
+ goto signed_number;
// unsigned decimal
case 'u':
- num = getuint(&ap, lflag);
base = 10;
- goto number;
+ goto unsigned_number;
// (unsigned) octal
case 'o':
// should do something with padding so it's always 3 octits
- num = getuint(&ap, lflag);
base = 8;
- goto number;
+ goto unsigned_number;
// pointer
case 'p':
+ static_assert(sizeof(long) == sizeof(void*));
+ lflag = 1;
putch('0', putdat);
putch('x', putdat);
- num = (unsigned long long)
- (uintptr_t) va_arg(ap, void *);
- base = 16;
- goto number;
+ /* fall through to 'x' */
// (unsigned) hexadecimal
case 'x':
- num = getuint(&ap, lflag);
base = 16;
- number:
+ unsigned_number:
+ num = getuint(&ap, lflag);
+ signed_number:
printnum(putch, putdat, num, base, width, padc);
break;
va_start(ap, fmt);
vprintfmt((void*)putchar, 0, fmt, ap);
- putchar(-1);
va_end(ap);
return 0; // incorrect return value, but who cares, anyway?
}
+
+int sprintf(char* str, const char* fmt, ...)
+{
+ va_list ap;
+ char* str0 = str;
+ va_start(ap, fmt);
+
+ void sprintf_putch(int ch, void** data)
+ {
+ char** pstr = (char**)data;
+ **pstr = ch;
+ (*pstr)++;
+ }
+
+ vprintfmt(sprintf_putch, (void**)&str, fmt, ap);
+ *str = 0;
+
+ va_end(ap);
+ return str - str0;
+}
+
+void* memcpy(void* dest, const void* src, size_t len)
+{
+ if ((((uintptr_t)dest | (uintptr_t)src | len) & (sizeof(uintptr_t)-1)) == 0) {
+ const uintptr_t* s = src;
+ uintptr_t *d = dest;
+ while (d < (uintptr_t*)(dest + len))
+ *d++ = *s++;
+ } else {
+ const char* s = src;
+ char *d = dest;
+ while (d < (char*)(dest + len))
+ *d++ = *s++;
+ }
+ return dest;
+}
+
+void* memset(void* dest, int byte, size_t len)
+{
+ if ((((uintptr_t)dest | len) & (sizeof(uintptr_t)-1)) == 0) {
+ uintptr_t word = byte & 0xFF;
+ word |= word << 8;
+ word |= word << 16;
+ word |= word << 16 << 16;
+
+ uintptr_t *d = dest;
+ while (d < (uintptr_t*)(dest + len))
+ *d++ = word;
+ } else {
+ char *d = dest;
+ while (d < (char*)(dest + len))
+ *d++ = byte;
+ }
+ return dest;
+}
+
+size_t strlen(const char *s)
+{
+ const char *p = s;
+ while (*p)
+ p++;
+ return p - s;
+}
+
+size_t strnlen(const char *s, size_t n)
+{
+ const char *p = s;
+ while (n-- && *p)
+ p++;
+ return p - s;
+}
+
+int strcmp(const char* s1, const char* s2)
+{
+ unsigned char c1, c2;
+
+ do {
+ c1 = *s1++;
+ c2 = *s2++;
+ } while (c1 != 0 && c1 == c2);
+
+ return c1 - c2;
+}
+
+char* strcpy(char* dest, const char* src)
+{
+ char* d = dest;
+ while ((*d++ = *src++))
+ ;
+ return dest;
+}
+
+long atol(const char* str)
+{
+ long res = 0;
+ int sign = 0;
+
+ while (*str == ' ')
+ str++;
+
+ if (*str == '-' || *str == '+') {
+ sign = *str == '-';
+ str++;
+ }
+
+ while (*str) {
+ res *= 10;
+ res += *str++ - '0';
+ }
+
+ return sign ? -res : res;
+}