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[POWERPC] 4xx: Add early udbg support for 40x processors

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This adds some basic real mode based early udbg support for 40x
in order to debug things more easily

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
This commit is contained in:
Benjamin Herrenschmidt
2007-12-21 15:39:26 +11:00
committed by Josh Boyer
parent 69c0785112
commit 9dae8afdf2
6 changed files with 90 additions and 0 deletions
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39
arch/powerpc/kernel/misc_32.S
View File

@@ -206,6 +206,45 @@ _GLOBAL(_nmask_and_or_msr)
isync
blr /* Done */
#ifdef CONFIG_40x
/*
* Do an IO access in real mode
*/
_GLOBAL(real_readb)
mfmsr r7
ori r0,r7,MSR_DR
xori r0,r0,MSR_DR
sync
mtmsr r0
sync
isync
lbz r3,0(r3)
sync
mtmsr r7
sync
isync
blr
/*
* Do an IO access in real mode
*/
_GLOBAL(real_writeb)
mfmsr r7
ori r0,r7,MSR_DR
xori r0,r0,MSR_DR
sync
mtmsr r0
sync
isync
stb r3,0(r4)
sync
mtmsr r7
sync
isync
blr
#endif /* CONFIG_40x */
/*
* Flush MMU TLB

3
arch/powerpc/kernel/udbg.c
View File

@@ -54,6 +54,9 @@ void __init udbg_early_init(void)
#elif defined(CONFIG_PPC_EARLY_DEBUG_44x)
/* PPC44x debug */
udbg_init_44x_as1();
#elif defined(CONFIG_PPC_EARLY_DEBUG_40x)
/* PPC40x debug */
udbg_init_40x_realmode();
#elif defined(CONFIG_PPC_EARLY_DEBUG_CPM)
udbg_init_cpm();
#endif

33
arch/powerpc/kernel/udbg_16550.c
View File

@@ -225,3 +225,36 @@ void __init udbg_init_44x_as1(void)
udbg_getc = udbg_44x_as1_getc;
}
#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
#ifdef CONFIG_PPC_EARLY_DEBUG_40x
static void udbg_40x_real_putc(char c)
{
if (udbg_comport) {
while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0)
/* wait for idle */;
real_writeb(c, &udbg_comport->thr); eieio();
if (c == '\n')
udbg_40x_real_putc('\r');
}
}
static int udbg_40x_real_getc(void)
{
if (udbg_comport) {
while ((real_readb(&udbg_comport->lsr) & LSR_DR) == 0)
; /* wait for char */
return real_readb(&udbg_comport->rbr);
}
return -1;
}
void __init udbg_init_40x_realmode(void)
{
udbg_comport = (struct NS16550 __iomem *)
CONFIG_PPC_EARLY_DEBUG_40x_PHYSADDR;
udbg_putc = udbg_40x_real_putc;
udbg_getc = udbg_40x_real_getc;
udbg_getc_poll = NULL;
}
#endif /* CONFIG_PPC_EARLY_DEBUG_40x */