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| author | Haavard Skinnemoen <haavard.skinnemoen@atmel.com> | 2010-08-12 13:52:54 +0700 |
|---|---|---|
| committer | Reinhard Meyer <u-boot@emk-elektronik.de> | 2010-09-03 15:13:02 +0200 |
| commit | 1f36f73fe70560a2bd286a7abc8530fdc93af9ae (patch) | |
| tree | 23ba61ced5254af43107e7d0de5b25b566ac78bb /board/earthlcd | |
| parent | 9cec2fc209a000655af77256a39ede7c7d441e56 (diff) | |
| download | blackbird-obmc-uboot-1f36f73fe70560a2bd286a7abc8530fdc93af9ae.tar.gz blackbird-obmc-uboot-1f36f73fe70560a2bd286a7abc8530fdc93af9ae.zip | |
avr32: Add simple paging support
Use the MMU hardware to set up 1:1 mappings between physical and virtual
addresses. This allows us to bypass the cache when accessing the flash
without having to do any physical-to-virtual address mapping in the CFI
driver.
The virtual memory mappings are defined at compile time through a sorted
array of virtual memory range objects. When a TLB miss exception
happens, the exception handler does a binary search through the array
until it finds a matching entry and loads it into the TLB. The u-boot
image itself is covered by a fixed TLB entry which is never replaced.
This makes the 'saveenv' command work again on ATNGW100 and other boards
using the CFI driver, hopefully without breaking any rules.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Diffstat (limited to 'board/earthlcd')
| -rw-r--r-- | board/earthlcd/favr-32-ezkit/favr-32-ezkit.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c b/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c index d2843c9d2b..b0eca939b7 100644 --- a/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c +++ b/board/earthlcd/favr-32-ezkit/favr-32-ezkit.c @@ -24,10 +24,25 @@ #include <asm/sdram.h> #include <asm/arch/clk.h> #include <asm/arch/hmatrix.h> +#include <asm/arch/mmu.h> #include <asm/arch/portmux.h> DECLARE_GLOBAL_DATA_PTR; +struct mmu_vm_range mmu_vmr_table[CONFIG_SYS_NR_VM_REGIONS] = { + { + .virt_pgno = CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT, + .nr_pages = CONFIG_SYS_FLASH_SIZE >> PAGE_SHIFT, + .phys = (CONFIG_SYS_FLASH_BASE >> PAGE_SHIFT) + | MMU_VMR_CACHE_NONE, + }, { + .virt_pgno = CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT, + .nr_pages = EBI_SDRAM_SIZE >> PAGE_SHIFT, + .phys = (CONFIG_SYS_SDRAM_BASE >> PAGE_SHIFT) + | MMU_VMR_CACHE_WRBACK, + }, +}; + static const struct sdram_config sdram_config = { /* MT48LC4M32B2P-6 (16 MB) */ .data_bits = SDRAM_DATA_32BIT, |
