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SubjectRe: HP Pavilion 8290 HANGS on boot 2.4/2.4-test9
Hi!

> >Is there a safe way to add debug information like simple string prints in
> >arch/i386/boot/compressed/head.s and in arch/i386/kernel/head.S
> >so that I can see at the console where the boot process hangs?
>
> Time for another version of my VIDEO_CHAR patch.]

What abourt early_printk? Works well on x86-64... And you can easily
redirect printk to early_printk.

#include <asm/io.h>


#ifndef MINIKERNEL
#define VGABASE 0xffffffff800b8000ul /* This is "wrong" address to access it, we should access it using 0xffff8000000b8000ul; but 0xffff8000000b8000ul is not available early at boot. */
#else
#define VGABASE 0xb8000ul
#endif

#define MAX_YPOS 25
#define MAX_XPOS 80

static int current_ypos = 1, current_xpos = 0; /* We want to print before clearing BSS */
int printk_ready = 0;

#ifndef MINIKERNEL
void
early_clear (void)
{
int k, i;
for(k = 0; k < MAX_YPOS; k++)
for(i = 0; i < MAX_XPOS; i++)
writew(0, VGABASE + 2*(MAX_XPOS*k + i));
current_ypos = 0;
}

void
early_puts (const char *str)
{
char c;
int i, k, j;

while ((c = *str++) != '\0') {
if (current_ypos >= MAX_YPOS) {
#ifndef CONFIG_SIMNOW
/* scroll 1 line up */
for(k = 1, j = 0; k < MAX_YPOS; k++, j++) {
for(i = 0; i < MAX_XPOS; i++) {
writew(readw(VGABASE + 2*(MAX_XPOS*k + i)),
VGABASE + 2*(MAX_XPOS*j + i));
}
}
for(i = 0; i < MAX_XPOS; i++) {
writew(0x720, VGABASE + 2*(MAX_XPOS*j + i));
}
current_ypos = MAX_YPOS-1;
#else
/* MUCH faster */
early_clear();
current_ypos = 0;
#endif
}
if (c == '\n') {
current_xpos = 0;
current_ypos++;
} else if (c != '\r') {
writew(((0x7 << 8) | (unsigned short) c),
VGABASE + 2*(MAX_XPOS*current_ypos + current_xpos++));
if (current_xpos >= MAX_XPOS) {
current_xpos = 0;
current_ypos++;
}
}
}
}
#else
#define putc(c, x) writew(((0x7 << 8) | (unsigned short) (c)), \
VGABASE + (x) * 2);

void
early_puts (const char *str)
{
char c;
int i, rest;

while ((c = *str++) != '\0') {
if (c == '\n' || c == '\r') {
/* blank rest of the line */
rest = MAX_XPOS - (current_xpos % MAX_XPOS);
for (i=0; i < rest; i++) {
putc(' ', current_xpos++);
}
} else {
putc(c, current_xpos);
current_xpos++;
}
current_xpos %= MAX_XPOS * MAX_YPOS;
}
}
#endif /* MINIKERNEL */

static char buf[1024];

int early_printk(const char *fmt, ...)
{
va_list args;
int i;

va_start(args, fmt);
i = vsprintf(buf, fmt, args); /* hopefully i < sizeof(buf)-4 */
va_end(args);

if (!printk_ready)
early_puts(buf);
else
printk("%s", buf);

return i;
}

--
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
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