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/platforms/44x | |
| parent | f6dfc80554b27da11dbb36ebae166b23ec3aa9ca (diff) | |
[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/platforms/44x')
| -rw-r--r-- | arch/powerpc/platforms/44x/44x.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/platforms/44x/misc_44x.S | 31 |
2 files changed, 33 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/44x/44x.h b/arch/powerpc/platforms/44x/44x.h index 45f24b166f4..42eabf87fea 100644 --- a/arch/powerpc/platforms/44x/44x.h +++ b/arch/powerpc/platforms/44x/44x.h @@ -1,6 +1,8 @@ #ifndef __POWERPC_PLATFORMS_44X_44X_H #define __POWERPC_PLATFORMS_44X_44X_H +extern u8 as1_readb(volatile u8 __iomem *addr); +extern void as1_writeb(u8 data, volatile u8 __iomem *addr); extern void ppc44x_reset_system(char *cmd); #endif /* __POWERPC_PLATFORMS_44X_44X_H */ diff --git a/arch/powerpc/platforms/44x/misc_44x.S b/arch/powerpc/platforms/44x/misc_44x.S index 52bde71485b..3bce71d5d75 100644 --- a/arch/powerpc/platforms/44x/misc_44x.S +++ b/arch/powerpc/platforms/44x/misc_44x.S @@ -15,6 +15,37 @@ .text /* + * Do an IO access in AS1 + */ +_GLOBAL(as1_readb) + mfmsr r7 + ori r0,r7,MSR_DS + sync + mtmsr r0 + sync + isync + lbz r3,0(r3) + sync + mtmsr r7 + sync + isync + blr + +_GLOBAL(as1_writeb) + mfmsr r7 + ori r0,r7,MSR_DS + sync + mtmsr r0 + sync + isync + stb r3,0(r4) + sync + mtmsr r7 + sync + isync + blr + +/* * void ppc44x_reset_system(char *cmd) * * At present, this routine just applies a system reset. |