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fixed (rough) comments

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This commit is contained in:
Markus Fröschle
2014-09-26 05:59:02 +00:00
parent f044fbbe72
commit 83666ba2f5
4 changed files with 41 additions and 39 deletions
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61
sys/mmu.c
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@@ -192,39 +192,39 @@ inline uint32_t set_mmubar(uint32_t value)
}
/*
* translation table for virtual addresses. Holds the virtual_offset (which must be added to a physical
* address to get its virtual counterpart) for memory ranges.
* Currently, this contains only the STRAM addresses which are mapped to Firebee video memory
* translation table for virtual address ranges. Holds the physical_offset (which must be added to a virtual
* address to get its physical counterpart) for memory ranges.
*/
struct phys_to_virt
struct virt_to_phys
{
uint32_t start_address;
uint32_t length;
uint32_t virtual_offset;
uint32_t physical_offset;
};
static struct phys_to_virt translation[] =
static struct virt_to_phys translation[] =
{
{ 0x00000000, 0x00e00000, 0x60000000 }, /* map first 14 MByte to first 16 Mb of video ram */
/* virtual , length , offset */
{ 0x00000000, 0x00e00000, 0x60000000 }, /* map first 14 MByte to first 14 Mb of video ram */
{ 0x00e00000, 0x00100000, 0x00000000 }, /* map TOS to SDRAM */
{ 0x00f00000, 0x00100000, 0xff000000 }, /* map Falcon I/O area to FPGA */
{ 0x01000000, 0x10000000, 0x00000000 }, /* map rest of ram virt = phys */
{ 0x1fd00000, 0x01000000, 0x00000000 }, /* accessed by EmuTOS? */
};
static int num_translations = sizeof(translation) / sizeof(struct phys_to_virt);
static int num_translations = sizeof(translation) / sizeof(struct virt_to_phys);
static inline uint32_t lookup_phys(uint32_t phys)
static inline uint32_t lookup_phys(uint32_t virt)
{
int i;
for (i = 0; i < num_translations; i++)
{
if (phys >= translation[i].start_address && phys < translation[i].start_address + translation[i].length)
if (virt >= translation[i].start_address && virt < translation[i].start_address + translation[i].length)
{
return phys + translation[i].virtual_offset;
return virt + translation[i].physical_offset;
}
}
err("physical address 0x%lx not found in translation table!\r\n", phys);
err("virtual address 0x%lx not found in translation table!\r\n", virt);
}
struct page_descriptor
@@ -241,7 +241,7 @@ struct page_descriptor
static struct page_descriptor pages[65536]; /* 512 Mb RAM */
/*
* map a page of memory using virt and phys as addresses with the Coldfire MMU.
* map a page of memory using virt addresses with the Coldfire MMU.
*
* Theory of operation: the Coldfire MMU in the Firebee has 64 TLB entries, 32 for data (DTLB), 32 for
* instructions (ITLB). Mappings can either be done locked (normal MMU TLB misses will not consider them
@@ -255,10 +255,10 @@ static struct page_descriptor pages[65536]; /* 512 Mb RAM */
int mmu_map_8k_page(uint32_t virt)
{
const int size_mask = 0xffffe000; /* 8k pagesize */
int page_index = (virt & size_mask) / 4096; /* index into page_descriptor array */
int page_index = (virt & size_mask) / 4096; /* index into page_descriptor array */
struct page_descriptor *page = &pages[page_index]; /* attributes of page to map */
uint32_t adr = lookup_phys(virt); /* phys2virt translation of page */
uint32_t addr = lookup_phys(virt); /* virtual to physical translation of page */
/*
* add page to TLB
@@ -269,7 +269,7 @@ int mmu_map_8k_page(uint32_t virt)
MCF_MMU_MMUTR_V; /* valid */
NOP();
MCF_MMU_MMUDR = (adr & size_mask) | /* physical address */
MCF_MMU_MMUDR = (addr & size_mask) | /* physical address */
MCF_MMU_MMUDR_SZ(MMU_PAGE_SIZE_8K) | /* page size */
MCF_MMU_MMUDR_CM(page->cache_mode) |
(page->read ? MCF_MMU_MMUDR_R : 0) | /* read access enable */
@@ -285,7 +285,7 @@ int mmu_map_8k_page(uint32_t virt)
MCF_MMU_MMUOR = MCF_MMU_MMUOR_ITLB | /* instruction */
MCF_MMU_MMUOR_ACC | /* access TLB */
MCF_MMU_MMUOR_UAA; /* update allocation address field */
dbg("mapped virt=0x%08x to phys=0x%08x\r\n", virt, adr);
dbg("mapped virt=0x%08x to phys=0x%08x\r\n", virt, addr);
return 1;
}
@@ -335,8 +335,7 @@ int mmu_map_page(uint32_t virt, uint32_t phys, enum mmu_page_size sz, const stru
break;
default:
dbg("illegal map size %d\r\n", sz);
return 0;
err("illegal map size %d\r\n", sz);
}
/*
@@ -377,13 +376,13 @@ void mmu_init(void)
int i;
/*
* prelaminary initialization of page descriptor table
* prelaminary initialization of page descriptor 0 (root) table
*/
for (i = 0; i < sizeof(pages); i++)
{
uint32_t adr = i * 8192;
uint32_t addr = i * DEFAULT_PAGE_SIZE;
if (adr >= 0x00f00000 && adr < 0x00ffffff)
if (addr >= 0x00f00000 && addr < 0x00ffffff)
{
pages[i].cache_mode = CACHE_NOCACHE_PRECISE;
}
@@ -391,20 +390,20 @@ void mmu_init(void)
{
pages[i].cache_mode = CACHE_COPYBACK;
}
pages[i].global = 1;
pages[i].locked = 0;
pages[i].read = 1;
pages[i].global = 1; /* all pages global by default */
pages[i].locked = 0; /* not locked */
pages[i].read = 1; /* readable, writable, executable */
pages[i].write = 1;
pages[i].execute = 1;
pages[i].supervisor_protect = 0;
pages[i].supervisor_protect = 0; /* not supervisor protected */
}
set_asid(0); /* do not use address extension (ASID provides virtual 48 bit addresses */
set_asid(0); /* do not use address extension (ASID provides virtual 48 bit addresses) yet */
/* set data access attributes in ACR0 and ACR1 */
set_acr0(ACR_W(0) | /* read and write accesses permitted */
ACR_SP(0) | /* supervisor and user mode access permitted */
ACR_CM(ACR_CM_CACHE_INH_PRECISE) | /* cache inhibit, precise */
ACR_CM(ACR_CM_CACHE_INH_PRECISE) | /* cache inhibit, precise (i/o area!) */
ACR_AMM(0) | /* control region > 16 MB */
ACR_S(ACR_S_ALL) | /* match addresses in user and supervisor mode */
ACR_E(1) | /* enable ACR */
@@ -426,7 +425,7 @@ void mmu_init(void)
ACR_SP(0) |
ACR_CM(0) |
#if defined(MACHINE_FIREBEE)
ACR_CM(ACR_CM_CACHEABLE_WT) | /* video RAM on the Firebee */
ACR_CM(ACR_CM_CACHEABLE_WT) | /* ST RAM on the Firebee */
#elif defined(MACHINE_M5484LITE)
ACR_CM(ACR_CM_CACHE_INH_PRECISE) | /* Compact Flash on the M548xLITE */
#elif defined(MACHINE_M54455)
@@ -442,7 +441,7 @@ void mmu_init(void)
/* set instruction access attributes in ACR2 and ACR3 */
//set_acr2(0xe007c400);
//set_acr2(0xe007c400); /* flash area */
set_acr2(ACR_W(0) |
ACR_SP(0) |
ACR_CM(0) |
@@ -469,6 +468,7 @@ void mmu_init(void)
*/
flags.cache_mode = CACHE_COPYBACK;
flags.access = ACCESS_READ | ACCESS_WRITE | ACCESS_EXECUTE;
flags.protection = SV_PROTECT; /* supervisor access only */
mmu_map_page(SDRAM_START + SDRAM_SIZE - 0X00200000, SDRAM_START + SDRAM_SIZE - 0X00200000, MMU_PAGE_SIZE_1M, &flags);
/*
@@ -489,6 +489,7 @@ void mmutr_miss(uint32_t address, uint32_t pc, uint32_t format_status)
#ifdef _NOT_USED_
// experimental; try to ensure that supervisor stack area stays in mmu TLBs
// guess what: doesn't work...
register uint32_t sp asm("sp");
if (sp < 0x02000000)
mmu_map_8k_page(sp);