From 5d2f271dce23b5fe8c1e6356380f228968343f2d Mon Sep 17 00:00:00 2001 From: ian Date: Sun, 7 Jan 2018 02:57:35 +0000 Subject: MFC r327222: Add a new ARM kernel option, LOCORE_MAP_MB, to control the size of the kernel VA mapping in the temporary page tables set up by locore-v6.S. The number used to be hard-coded to 64MB, which is still the default if the kernel option is not specified. However, 64MB is insufficient for using a large mdroot filesystem. The hard-coded number can't be safely increased because too large a number may run into memory-mapped IO space on some SoCs that must not be mapped as ordinary memory. --- sys/arm/arm/genassym.c | 9 +++++++++ sys/arm/arm/locore-v6.S | 11 ++++++++--- 2 files changed, 17 insertions(+), 3 deletions(-) (limited to 'sys/arm') diff --git a/sys/arm/arm/genassym.c b/sys/arm/arm/genassym.c index 3d11acd..b5cc952 100644 --- a/sys/arm/arm/genassym.c +++ b/sys/arm/arm/genassym.c @@ -161,3 +161,12 @@ ASSYM(DCACHE_LINE_SIZE, offsetof(struct cpuinfo, dcache_line_size)); ASSYM(DCACHE_LINE_MASK, offsetof(struct cpuinfo, dcache_line_mask)); ASSYM(ICACHE_LINE_SIZE, offsetof(struct cpuinfo, icache_line_size)); ASSYM(ICACHE_LINE_MASK, offsetof(struct cpuinfo, icache_line_mask)); + +/* + * Emit the LOCORE_MAP_MB option as a #define only if the option was set. + */ +#include "opt_locore.h" + +#ifdef LOCORE_MAP_MB +ASSYM(LOCORE_MAP_MB, LOCORE_MAP_MB); +#endif diff --git a/sys/arm/arm/locore-v6.S b/sys/arm/arm/locore-v6.S index 10aaace..775b867 100644 --- a/sys/arm/arm/locore-v6.S +++ b/sys/arm/arm/locore-v6.S @@ -38,6 +38,10 @@ __FBSDID("$FreeBSD$"); +/* We map 64MB of kernel unless overridden in assym.s by the kernel option. */ +#ifndef LOCORE_MAP_MB +#define LOCORE_MAP_MB 64 +#endif #if __ARM_ARCH >= 7 #if defined(__ARM_ARCH_7VE__) || defined(__clang__) @@ -172,12 +176,13 @@ ASENTRY_NP(_start) bl build_pagetables /* - * Next we do 64MiB starting at the physical load address, mapped to - * the VA the kernel is linked for. + * Next we map the kernel starting at the physical load address, mapped + * to the VA the kernel is linked for. The default size we map is 64MiB + * but it can be overridden with a kernel option. */ mov r1, r5 ldr r2, =(KERNVIRTADDR) - mov r3, #64 + ldr r3, =(LOCORE_MAP_MB) bl build_pagetables /* Create a device mapping for early_printf if specified. */ -- cgit v1.1