Re: [crash, bisected] Re: [PATCH 3/4] x86_64: Fold pda into per cpu area

From: Eric W. Biederman
Date: Tue Jul 08 2008 - 19:42:17 EST

Mike Travis <travis@xxxxxxx> writes:

> Unfortunately it's back to the problem of faulting before x86_64_start_kernel()
> and grub just immediately reboots. So I'm back at analyzing assembler and
> config differences.

Ok. That is a narrow window of code. So it shouldn't be too bad, nasty though.

If you would like to trace through it I have attached my serial port
debugging routines that I use in that part of the code.

Eric

#if 1
/* Base Address */
#define TTYS0_BASE 0x3f8
/* Data */
#define TTYS0_RBR (TTYS0_BASE+0x00)
#define TTYS0_TBR (TTYS0_BASE+0x00)
/* Control */
#define TTYS0_IER (TTYS0_BASE+0x01)
#define TTYS0_IIR (TTYS0_BASE+0x02)
#define TTYS0_FCR (TTYS0_BASE+0x02)
#define TTYS0_LCR (TTYS0_BASE+0x03)
#define TTYS0_MCR (TTYS0_BASE+0x04)

#define TTYS0_DLL (TTYS0_BASE+0x00)
#define TTYS0_DLM (TTYS0_BASE+0x01)
/* Status */
#define TTYS0_LSR (TTYS0_BASE+0x05)
#define TTYS0_MSR (TTYS0_BASE+0x06)
#define TTYS0_SCR (TTYS0_BASE+0x07)

#define TTYS0_BAUD 9600
#define TTYS0_DIV (115200/TTYS0_BAUD)
#define TTYS0_DIV_LO (TTYS0_DIV&0xFF)
#define TTYS0_DIV_HI ((TTYS0_DIV >> 8)&0xFF)

#if ((115200%TTYS0_BAUD) != 0)
#error Bad ttyS0 baud rate
#endif

#define TTYS0_INIT \
/* disable interrupts */ \
movb $0x00, %al ; \
movw $TTYS0_IER, %dx ; \
outb %al, %dx ; \
; \
/* enable fifos */ \
movb $0x01, %al ; \
movw $TTYS0_FCR, %dx ; \
outb %al, %dx ; \
; \
/* Set Baud Rate Divisor to TTYS0_BAUD */ \
movw $TTYS0_LCR, %dx ; \
movb $0x83, %al ; \
outb %al, %dx ; \
; \
movw $TTYS0_DLL, %dx ; \
movb $TTYS0_DIV_LO, %al ; \
outb %al, %dx ; \
; \
movw $TTYS0_DLM, %dx ; \
movb $TTYS0_DIV_HI, %al ; \
outb %al, %dx ; \
; \
movw $TTYS0_LCR, %dx ; \
movb $0x03, %al ; \
outb %al, %dx


/* uses: ax, dx */
#define TTYS0_TX_AL \
mov %al, %ah ; \
9: mov $TTYS0_LSR, %dx ; \
inb %dx, %al ; \
test $0x20, %al ; \
je 9b ; \
mov $TTYS0_TBR, %dx ; \
mov %ah, %al ; \
outb %al, %dx

/* uses: ax, dx */
#define TTYS0_TX_CHAR(byte) \
mov byte, %al ; \
TTYS0_TX_AL

/* uses: eax, dx */
#define TTYS0_TX_HEX32(lword) \
mov lword, %eax ; \
shr $28, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %eax ; \
shr $24, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %eax ; \
shr $20, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %eax ; \
shr $16, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %eax ; \
shr $12, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %eax ; \
shr $8, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %eax ; \
shr $4, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %eax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL

/* uses: rax, dx */
#define TTYS0_TX_HEX64(lword) \
mov lword, %rax ; \
shr $60, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $56, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $52, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $48, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $44, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $40, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $36, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $32, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $28, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $24, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $20, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $16, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $12, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $8, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
shr $4, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL ; \
; \
mov lword, %rax ; \
and $0x0f, %al ; \
add $'0', %al ; \
cmp $'9', %al ; \
jle 9f ; \
add $39, %al ; \
9: ; \
TTYS0_TX_AL


#define DEBUG(x) TTYS0_TX_CHAR($x) ; TTYS0_TX_CHAR($'\r') ; TTYS0_TX_CHAR($'\n')
#define DEBUG_TX_HEX32(x) TTYS0_TX_HEX32(x); TTYS0_TX_CHAR($'\r') ; TTYS0_TX_CHAR($'\n')
#define DEBUG_TX_HEX64(x) TTYS0_TX_HEX64(x); TTYS0_TX_CHAR($'\r') ; TTYS0_TX_CHAR($'\n')
#endif