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void myprintf (const char *str)
{
??? char c; ???
??? while((c = *str++))
??????asm volatile("int $0x10":: "a"(0x0e00 | (c & 0xff)), "b"(7));
}Oh yes it is. At least the implementation of GCC on x86es as of 3.3.1 converts chars to ints as if they were signed (is this politically correct or what?) so you need to mask the top half/quarter.Schol-R-LEA wrote: Do you know where the code is from? I'm puzzled by this, not only because (as has been pointed out) it won't work in p-mode, but also becuase the part "c & 0xff" seems redundant - it gives the value of c, no more and no less. The inly thing I can think of is that it's because of the implicit cast from char to int, and is needed to ensure that the upper byte is cleared - but that shouldn't be necessary, should it?
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// ipl1.c - IPL sample
asm("
???ljmp???$0x7C0, $entry???
???movw???%cs, %ax???# AX := CS
???movw???%ax, %ds???# DS := AX
???movw???%ax, %es???# ES := AX
???movw???%ax, %ss???# SS := AX
???movw???$0xFFF0, %sp???# SP := FFF0h
???call???main??????
loop:????????????
???jmp???loop
");
BIOS Video Service: Write in Teletype Mode
INT 10h
AH= 0Eh
AL= character to write
BH= active page number
BL= foreground color
asm volatile("int $0x10":: "a"(0x0e00 | (c & 0xff)), "b"(7));
???movl???$(0x0e00|cの猛), %eax
???movl???$7, %ebx
???int???$0x10
void p(const char *str)
{
char c;
while((c = *str++))
asm volatile("int $0x10":: "a"(0x0e00 | (c & 0xff)), "b"(7));
}
int
main(void)
{
p("CORON\r\n");
return 0;
}
Make of it what you want, this babelfish isn't perfectbabelfish wrote: /*** default, gcc being to output the assembly for protect mode
cannot move with real mode. Because of of that of the code16gcc appointing, that with assembler gas it assembles the output of gcc in the one for real mode, you indicate. */
asm("code16gcc");
/***
When IPL is called, (CS=0, IP=7C00h) with it has become.
IPL itself in compile-time, being the to have allocated address the first as 0, addressing jump is done once, the forefront of
IP=0 and the program agrees to a CS=7C0h. Unless the so it does, treatment of address solves those of compile-time to be, it is different and does abnormal operation. After the jump (the address of CS=7C0h and IP=entry) with it becomes. Each segmented register after DS this of the, ES and SS is initialized with CS, stack pointer SP is initialized and main function is called. */
but it does output somewhat legible sentences. You indeed need .code16gcc for gcc to output 16-bit code, and the second comment block (made somewhat more legible by removing the line numbers and adding the */'s which babelfish rips out) indicates how the code is loaded more or less. PS: do check with the code itself, I don't completely trust the comment.Someone asked for the standard? Huh? Huh?Candy wrote: At least the implementation of GCC on x86es as of 3.3.1 converts chars to ints as if they were signed (is this politically correct or what?)...
