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modified to map memory dynamically based on a static memory map

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This commit is contained in:
Markus Fröschle
2014-01-18 08:04:44 +00:00
parent b02fddc178
commit 9f76db9561
3 changed files with 55 additions and 6 deletions
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2
BaS_gcc/Makefile
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@@ -9,7 +9,7 @@
# can be either "Y" or "N" (without quotes). "Y" for using the m68k-elf-, "N" for using the m68k-atari-mint
# toolchain
COMPILE_ELF=N
COMPILE_ELF=Y
ifeq (Y,$(COMPILE_ELF))
TCPREFIX=m68k-elf-

11
BaS_gcc/include/mmu.h
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@@ -56,11 +56,22 @@
#define SCA_PAGE_ID 6 /* indicates video memory page */
/*
* MMU page sizes
*/
#define MMU_PAGE_SIZE_1M 0
#define MMU_PAGE_SIZE_4K 1
#define MMU_PAGE_SIZE_8K 2
#define MMU_PAGE_SIZE_1K 3
/*
* MMU cache modes
*/
#define MMU_CACHE_WRITETHROUGH 0
#define MMU_CACHE_COPYBACK 1
#define MMU_CACHE_NOCACHE_PRECISE 2
#define MMU_CACHE_NOCACHE_IMPRECISE 3
/*
* global variables from linker script
*/

48
BaS_gcc/sys/mmu.c
View File

@@ -337,6 +337,49 @@ void mmu_init(void)
}
/*
* TODO: this would be nicer in an include file
*/
extern uint8_t _MBAR[];
extern uint8_t _RAMBAR0[];
extern uint8_t _RAMBAR1[];
extern uint8_t _SYS_SRAM[];
extern uint8_t _SYS_SRAM_SIZE[];
static struct mmu_mapping
{
uint32_t phys;
uint32_t virt;
uint32_t length;
uint32_t pagesize;
uint32_t flags;
} memory_map[] =
{
{
_RAMBAR0,
_RAMBAR0,
_RAMBAR0_SIZE,
MMU_PAGE_SIZE_1K,
MMU_CACHE_WRITETHROUGH,
},
{
_RAMBAR1,
_RAMBAR1,
_RAMBAR1_SIZE,
MMU_PAGE_SIZE_1K,
MMU_CACHE_WRITETHROUGH,
},
{
_SYS_SRAM,
_SYS_SRAM,
_SYS_SRAM_SIZE,
MMU_PAGE_SIZE_1K,
MMU_CACHE_WRITETHROUGH,
}
};
static int num_mmu_maps = sizeof(memory_map) / sizeof(struct mmu_mapping);
/*
* handle an access error
* upper level routine called from access_exception inside exceptions.S
@@ -383,11 +426,6 @@ bool access_exception(uint32_t pc, uint32_t format_status)
}
else
{
extern uint8_t _RAMBAR0[];
extern uint8_t _RAMBAR1[];
extern uint8_t _SYS_SRAM[];
extern uint8_t _SYS_SRAM_SIZE[];
uint32_t flags;
/* TODO: MBAR, MMUBAR, PCI MEMORY, PCI IO, DMA BUFFERS */