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.
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?).
-Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
