// Misc utility functions.
//
-// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "farptr.h" // GET_FLATPTR
#include "biosvar.h" // get_ebda_seg
+static inline u32 getesp() {
+ u32 esp;
+ asm("movl %%esp, %0" : "=rm"(esp));
+ return esp;
+}
+
+
+/****************************************************************
+ * 16bit calls
+ ****************************************************************/
+
// Call a function with a specified register state. Note that on
// return, the interrupt enable/disable flag may be altered.
inline void
call16(struct bregs *callregs)
{
+ if (!MODE16 && getesp() > BUILD_STACK_ADDR)
+ panic("call16 with invalid stack\n");
asm volatile(
#if MODE16 == 1
"calll __call16\n"
+ "cli\n"
+ "cld"
#else
- "calll __call16_from32\n"
+ "calll __call16_from32"
#endif
: "+a" (callregs), "+m" (*callregs)
:
- : "ebx", "ecx", "edx", "esi", "edi", "ebp", "cc", "memory");
+ : "ebx", "ecx", "edx", "esi", "edi", "cc", "memory");
}
inline void
call16big(struct bregs *callregs)
{
- extern void __force_link_error__call16big_only_in_32bit_mode();
- if (MODE16)
- __force_link_error__call16big_only_in_32bit_mode();
-
+ ASSERT32();
+ if (getesp() > BUILD_STACK_ADDR)
+ panic("call16 with invalid stack\n");
asm volatile(
- "calll __call16big_from32\n"
+ "calll __call16big_from32"
: "+a" (callregs), "+m" (*callregs)
:
- : "ebx", "ecx", "edx", "esi", "edi", "ebp", "cc", "memory");
+ : "ebx", "ecx", "edx", "esi", "edi", "cc", "memory");
}
inline void
__call16_int(struct bregs *callregs, u16 offset)
{
if (MODE16)
- callregs->cs = GET_SEG(CS);
+ callregs->code.seg = GET_SEG(CS);
else
- callregs->cs = SEG_BIOS;
- callregs->ip = offset;
+ callregs->code.seg = SEG_BIOS;
+ callregs->code.offset = offset;
call16(callregs);
}
-inline void
-call16_simpint(int nr, u32 *eax, u32 *flags)
-{
- extern void __force_link_error__call16_simpint_only_in_16bit_mode();
- if (!MODE16)
- __force_link_error__call16_simpint_only_in_16bit_mode();
-
- asm volatile(
- "stc\n"
- "int %2\n"
- "pushfl\n"
- "popl %1\n"
- "cld\n"
- "cli\n"
- : "+a"(*eax), "=r"(*flags)
- : "i"(nr)
- : "cc", "memory");
-}
-
// Switch to the extra stack in ebda and call a function.
inline u32
stack_hop(u32 eax, u32 edx, u32 ecx, void *func)
{
- extern void __force_link_error__stack_hop_only_in_16bit_mode();
- if (!MODE16)
- __force_link_error__stack_hop_only_in_16bit_mode();
-
+ ASSERT16();
u16 ebda_seg = get_ebda_seg(), bkup_ss;
u32 bkup_esp;
asm volatile(
// Restore segments and stack
"movw %w3, %%ds\n"
"movw %w3, %%ss\n"
- "movl %4, %%esp\n"
+ "movl %4, %%esp"
: "+a" (eax), "+d" (edx), "+c" (ecx), "=&r" (bkup_ss), "=&r" (bkup_esp)
: "i" (EBDA_OFFSET_TOP_STACK), "r" (ebda_seg), "m" (*(u8*)func)
: "cc", "memory");
return eax;
}
+// 16bit trampoline for enabling irqs from 32bit mode.
+ASM16(
+ " .global trampoline_checkirqs\n"
+ "trampoline_checkirqs:\n"
+ " rep ; nop\n"
+ " lretw"
+ );
+
+static void
+check_irqs32()
+{
+ extern void trampoline_checkirqs();
+ struct bregs br;
+ br.flags = F_IF;
+ br.code.seg = SEG_BIOS;
+ br.code.offset = (u32)&trampoline_checkirqs;
+ call16big(&br);
+}
+
+static void
+check_irqs16()
+{
+ asm volatile(
+ "sti\n"
+ "nop\n"
+ "rep ; nop\n"
+ "cli\n"
+ "cld\n"
+ : : :"memory");
+}
+
+
+/****************************************************************
+ * Threads
+ ****************************************************************/
+
+#define THREADSTACKSIZE 4096
+
+struct thread_info {
+ struct thread_info *next;
+ void *stackpos;
+};
+
+struct thread_info MainThread;
+
+void
+thread_setup()
+{
+ MainThread.next = &MainThread;
+ MainThread.stackpos = NULL;
+}
+
+struct thread_info *
+getCurThread()
+{
+ u32 esp = getesp();
+ if (esp <= BUILD_STACK_ADDR)
+ return &MainThread;
+ return (void*)ALIGN_DOWN(esp, THREADSTACKSIZE);
+}
+
+// Briefly permit irqs to occur.
+void
+yield()
+{
+ if (MODE16) {
+ // In 16bit mode, just directly check irqs.
+ check_irqs16();
+ return;
+ }
+ if (! CONFIG_THREADS) {
+ check_irqs32();
+ return;
+ }
+ struct thread_info *cur = getCurThread();
+ if (cur == &MainThread)
+ // Permit irqs to fire
+ check_irqs32();
+
+ // Switch to the next thread
+ struct thread_info *next = cur->next;
+ asm volatile(
+ " pushl $1f\n" // store return pc
+ " pushl %%ebp\n" // backup %ebp
+ " movl %%esp, 4(%%eax)\n" // cur->stackpos = %esp
+ " movl 4(%%ecx), %%esp\n" // %esp = next->stackpos
+ " popl %%ebp\n" // restore %ebp
+ " retl\n" // restore pc
+ "1:\n"
+ : "+a"(cur), "+c"(next)
+ :
+ : "ebx", "edx", "esi", "edi", "cc", "memory");
+}
+
+// Last thing called from a thread (called on "next" stack).
+static void
+__end_thread(struct thread_info *old)
+{
+ struct thread_info *pos = &MainThread;
+ while (pos->next != old)
+ pos = pos->next;
+ pos->next = old->next;
+ free(old);
+ dprintf(DEBUG_thread, "\\%08x/ End thread\n", (u32)old);
+}
+
+void
+run_thread(void (*func)(void*), void *data)
+{
+ ASSERT32();
+ if (! CONFIG_THREADS)
+ goto fail;
+ struct thread_info *thread;
+ thread = memalign_tmphigh(THREADSTACKSIZE, THREADSTACKSIZE);
+ if (!thread)
+ goto fail;
+
+ thread->stackpos = (void*)thread + THREADSTACKSIZE;
+ struct thread_info *cur = getCurThread();
+ thread->next = cur->next;
+ cur->next = thread;
+
+ dprintf(DEBUG_thread, "/%08x\\ Start thread\n", (u32)thread);
+ asm volatile(
+ // Start thread
+ " pushl $1f\n" // store return pc
+ " pushl %%ebp\n" // backup %ebp
+ " movl %%esp, 4(%%edx)\n" // cur->stackpos = %esp
+ " movl 4(%%ebx), %%esp\n" // %esp = thread->stackpos
+ " calll *%%ecx\n" // Call func
+
+ // End thread
+ " movl (%%ebx), %%ecx\n" // %ecx = thread->next
+ " movl 4(%%ecx), %%esp\n" // %esp = next->stackpos
+ " movl %%ebx, %%eax\n"
+ " calll %4\n" // call __end_thread(thread)
+ " popl %%ebp\n" // restore %ebp
+ " retl\n" // restore pc
+ "1:\n"
+ : "+a"(data), "+c"(func), "+b"(thread), "+d"(cur)
+ : "m"(*(u8*)__end_thread)
+ : "esi", "edi", "cc", "memory");
+ return;
+
+fail:
+ func(data);
+}
+
+void
+wait_threads()
+{
+ ASSERT32();
+ if (! CONFIG_THREADS)
+ return;
+ while (MainThread.next != &MainThread)
+ yield();
+}
+
+
+/****************************************************************
+ * String ops
+ ****************************************************************/
+
// Sum the bytes in the specified area.
u8
-checksum_far(u16 buf_seg, u8 *buf_far, u32 len)
+checksum_far(u16 buf_seg, void *buf_far, u32 len)
{
SET_SEG(ES, buf_seg);
u32 i;
u8 sum = 0;
for (i=0; i<len; i++)
- sum += GET_VAR(ES, buf_far[i]);
+ sum += GET_VAR(ES, ((u8*)buf_far)[i]);
return sum;
}
u8
-checksum(u8 *buf, u32 len)
+checksum(void *buf, u32 len)
{
return checksum_far(GET_SEG(SS), buf, len);
}
+size_t
+strlen(const char *s)
+{
+ if (__builtin_constant_p(s))
+ return __builtin_strlen(s);
+ const char *p = s;
+ while (*p)
+ p++;
+ return p-s;
+}
+
+// Compare two areas of memory.
+int
+memcmp(const void *s1, const void *s2, size_t n)
+{
+ while (n) {
+ if (*(u8*)s1 != *(u8*)s2)
+ return *(u8*)s1 < *(u8*)s2 ? -1 : 1;
+ s1++;
+ s2++;
+ n--;
+ }
+ return 0;
+}
+
+// Compare two strings.
+int
+strcmp(const char *s1, const char *s2)
+{
+ for (;;) {
+ if (*s1 != *s2)
+ return *s1 < *s2 ? -1 : 1;
+ if (! *s1)
+ return 0;
+ s1++;
+ s2++;
+ }
+}
+
+inline void
+memset_far(u16 d_seg, void *d_far, u8 c, size_t len)
+{
+ SET_SEG(ES, d_seg);
+ asm volatile(
+ "rep stosb %%es:(%%di)"
+ : "+c"(len), "+D"(d_far)
+ : "a"(c)
+ : "cc", "memory");
+}
+
+inline void
+memset16_far(u16 d_seg, void *d_far, u16 c, size_t len)
+{
+ len /= 2;
+ SET_SEG(ES, d_seg);
+ asm volatile(
+ "rep stosw %%es:(%%di)"
+ : "+c"(len), "+D"(d_far)
+ : "a"(c)
+ : "cc", "memory");
+}
+
void *
memset(void *s, int c, size_t n)
{
"movw %%ds, %w0\n"
"movw %w4, %%ds\n"
"rep movsb (%%si),%%es:(%%di)\n"
- "movw %w0, %%ds\n"
+ "movw %w0, %%ds"
: "=&r"(bkup_ds), "+c"(len), "+S"(s_far), "+D"(d_far)
: "r"(s_seg)
: "cc", "memory");
}
void *
+#undef memcpy
memcpy(void *d1, const void *s1, size_t len)
+#if MODE16 == 0
+#define memcpy __builtin_memcpy
+#endif
{
- u8 *d = (u8*)d1, *s = (u8*)s1;
- while (len--)
- *d++ = *s++;
+ SET_SEG(ES, GET_SEG(SS));
+ void *d = d1;
+ if (((u32)d1 | (u32)s1 | len) & 3) {
+ // non-aligned memcpy
+ asm volatile(
+ "rep movsb (%%esi),%%es:(%%edi)"
+ : "+c"(len), "+S"(s1), "+D"(d)
+ : : "cc", "memory");
+ return d1;
+ }
+ // Common case - use 4-byte copy
+ len /= 4;
+ asm volatile(
+ "rep movsl (%%esi),%%es:(%%edi)"
+ : "+c"(len), "+S"(s1), "+D"(d)
+ : : "cc", "memory");
return d1;
}
+// Copy from memory mapped IO. IO mem is very slow, so yield
+// periodically. 'len' must be 4 byte aligned.
+void
+iomemcpy(void *d, const void *s, u32 len)
+{
+ yield();
+ while (len) {
+ u32 copylen = len;
+ if (copylen > 1024)
+ copylen = 1024;
+ len -= copylen;
+ copylen /= 4;
+ asm volatile(
+ "rep movsl (%%esi),%%es:(%%edi)"
+ : "+c"(copylen), "+S"(s), "+D"(d)
+ : : "cc", "memory");
+ yield();
+ }
+}
+
void *
memmove(void *d, const void *s, size_t len)
{
return d;
}
-// Wait for 'usec' microseconds with irqs enabled.
-static void
-usleep(u32 usec)
+// Copy a string - truncating it if necessary.
+char *
+strtcpy(char *dest, const char *src, size_t len)
+{
+ char *d = dest;
+ while (len-- && *src != '\0')
+ *d++ = *src++;
+ *d = '\0';
+ return dest;
+}
+
+
+/****************************************************************
+ * Keyboard calls
+ ****************************************************************/
+
+// Wait for 'usec' microseconds using (with irqs enabled) using int 1586.
+void
+biosusleep(u32 usec)
{
struct bregs br;
memset(&br, 0, sizeof(br));
+ br.flags = F_IF;
br.ah = 0x86;
br.cx = usec >> 16;
br.dx = usec;
{
struct bregs br;
memset(&br, 0, sizeof(br));
+ br.flags = F_IF;
br.ah = 1;
call16_int(0x16, &br);
return !(br.flags & F_ZF);
{
struct bregs br;
memset(&br, 0, sizeof(br));
+ br.flags = F_IF;
call16_int(0x16, &br);
return br.ah;
}
return get_raw_keystroke();
if (msec <= 0)
return -1;
- usleep(50*1000);
+ biosusleep(50*1000);
msec -= 50;
}
}