Scott Wood wrote: > On 05/28/2010 10:18 AM, Martyn Welch wrote: >> The CPM early debug console hardcodes the BAT to cover the IMMR at >> 0xf0000000. The IMMR (on the mpc8270 at the very least) can be set to a >> number of locations with bootstrap configuration, which are outside the >> hardcoded BAT configuration. >> >> This patch determines the correct location at which to configure a BAT >> during the boot process from the supplied PPC_EARLY_DEBUG_CPM_ADDR. >> >> Signed-off-by: Martyn Welch<martyn.we...@ge.com> >> --- >> >> arch/powerpc/kernel/head_32.S | 5 +++-- >> arch/powerpc/sysdev/cpm_common.c | 4 +++- >> 2 files changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/arch/powerpc/kernel/head_32.S >> b/arch/powerpc/kernel/head_32.S >> index e025e89..861cace 100644 >> --- a/arch/powerpc/kernel/head_32.S >> +++ b/arch/powerpc/kernel/head_32.S >> @@ -1194,12 +1194,13 @@ setup_disp_bat: >> #endif /* CONFIG_BOOTX_TEXT */ >> >> #ifdef CONFIG_PPC_EARLY_DEBUG_CPM >> +#define PPC_EARLY_DEBUG_CPM_ADDR >> ASM_CONST(CONFIG_PPC_EARLY_DEBUG_CPM_ADDR) >> setup_cpm_bat: >> - lis r8, 0xf000 >> + lis r8, ppc_early_debug_cpm_a...@ha >> ori r8, r8, 0x002a >> mtspr SPRN_DBAT1L, r8 >> >> - lis r11, 0xf000 >> + lis r11, ppc_early_debug_cpm_a...@ha >> ori r11, r11, (BL_1M << 2) | 2 >> mtspr SPRN_DBAT1U, r11 > > Only the physical address should depend on where IMMR is. We should > use fixmap instead of an arbitrary address for the effective address. > There's a existing FIX_EARLY_DEBUG_BASE, but it's only 128 KiB so > we'll have to either grow it, or map only a subset of IMMR. >
I think that's a more fundamental change to CPM early debug than I can handle right now. > Plus, CONFIG_PPC_EARLY_DEBUG_CPM_ADDR points to the TX descriptor, not > to the beginning of IMMR, so you should mask off the lower 20 bits > (the offset is probably less than 64K, and the BAT might just ignore > the extra bits anyway, but why take chances?). > I assume that an extra instruction "andi r8, r8, 0xfff0" after each "lis" instruction would be what you are looking for? Martyn > -Scott -- Martyn Welch (Principal Software Engineer) | Registered in England and GE Intelligent Platforms | Wales (3828642) at 100 T +44(0)127322748 | Barbirolli Square, Manchester, E martyn.we...@ge.com | M2 3AB VAT:GB 927559189 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
