Messages in this thread | | | Date | Tue, 16 Jan 2001 12:18:45 +0100 | From | Pavel Machek <> | Subject | Re: 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
| |