diff options
| author |   David Gibson <david@gibson.dropbear.id.au> | 2007-05-08 12:59:31 +1000 |
|---|---|---|
| committer |   Paul Mackerras <paulus@samba.org> | 2007-05-08 14:47:33 +1000 |
| commit | d9b55a03611ff2e2e54fb4e1ad2648d5eb870fa3 (patch) | |
| tree | 5704be539afcd6f29b1f5751476c8b4f53673bff /arch/powerpc/kernel/head_44x.S | |
| parent | [POWERPC] Support for the Ebony 440GP reference board in arch/powerpc (diff) | |
| download | linux-dev-d9b55a03611ff2e2e54fb4e1ad2648d5eb870fa3.tar.xz linux-dev-d9b55a03611ff2e2e54fb4e1ad2648d5eb870fa3.zip | |
[POWERPC] Early serial debug support for PPC44x
This adds support for early serial debugging via the built in
port on IBM/AMCC PowerPC 44x CPUs. It uses a bolted TLB entry in
address space 1 for the UART's mapping, allowing robust debugging both
before and after the initialization of the MMU.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/head_44x.S')
| -rw-r--r-- | arch/powerpc/kernel/head_44x.S | 34 |
1 files changed, 13 insertions, 21 deletions
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index a51026f0a9d7..88695963f587 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -172,36 +172,28 @@ skpinv: addi r4,r4,1 /* Increment */ isync 4: -#ifdef CONFIG_SERIAL_TEXT_DEBUG - /* - * Add temporary UART mapping for early debug. - * We can map UART registers wherever we want as long as they don't - * interfere with other system mappings (e.g. with pinned entries). - * For an example of how we handle this - see ocotea.h. --ebs - */ +#ifdef CONFIG_PPC_EARLY_DEBUG_44x + /* Add UART mapping for early debug. */ + /* pageid fields */ - lis r3,UART0_IO_BASE@h - ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K + lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h + ori r3,r3,PPC44x_TLB_VALID|PPC44x_TLB_TS|PPC44x_TLB_64K /* xlat fields */ - lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */ -#ifndef CONFIG_440EP - ori r4,r4,0x0001 /* ERPN is 1 for second 4GB page */ -#endif + lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h + ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH /* attrib fields */ - li r5,0 - ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G) + li r5,(PPC44x_TLB_SW|PPC44x_TLB_SR|PPC44x_TLB_I|PPC44x_TLB_G) + li r0,62 /* TLB slot 0 */ - li r0,0 /* TLB slot 0 */ - - tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */ - tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */ - tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */ + tlbwe r3,r0,PPC44x_TLB_PAGEID + tlbwe r4,r0,PPC44x_TLB_XLAT + tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Force context change */ isync -#endif /* CONFIG_SERIAL_TEXT_DEBUG */ +#endif /* CONFIG_PPC_EARLY_DEBUG_44x */ /* Establish the interrupt vector offsets */ SET_IVOR(0, CriticalInput); |