| 73,10 → 73,11 |
|---|
| |
| #ifndef __ASM__ |
| |
| |
| /** Page table level 0 entry - "section" format (one-level paging, 1MB sized |
| * pages). Used only for booting the kernel. */ |
| typedef struct { |
| unsigned descriptor_type : 2; // PTE_DESCRIPTOR_SECTION (0b10) |
| unsigned descriptor_type : 2; |
| unsigned bufferable : 1; |
| unsigned cacheable : 1; |
| unsigned impl_specific : 1; |
| 88,23 → 89,55 |
|---|
| } __attribute__ ((packed)) pte_level0_section; |
| |
| |
| /** Page table that holds 1:1 mapping for booting the kernel. */ |
| extern pte_level0_section page_table[PTL0_ENTRIES_ARCH]; |
| |
| |
| /** Starts the MMU - initializes page table and enables paging. */ |
| void mmu_start(void); |
| |
| |
| /** Enables paging. */ |
| static inline void enable_paging() |
| { |
| /* c3 - each two bits controls access to the one of domains (16) |
| * 0b01 - behave as a client (user) of a domain |
| */ |
| asm volatile ( |
| // behave as a client of domains |
| "ldr r0, =0x55555555 \n" |
| "mcr p15, 0, r0, c3, c0, 0 \n" |
| // current settings |
| "mrc p15, 0, r0, c1, c0, 0 \n" |
| /* TODO: talk to Alf why needed |
| // mask to disable aligment checks; system & rom bit set to 0 (has no |
| // special effect) |
| "ldr r1, =0xfffffe8f \n" |
| "and r0, r0, r1 \n" |
| */ |
| // mask to enable paging |
| "ldr r1, =0x00000001 \n" |
| "orr r0, r0, r1 \n" |
| // store settings |
| "mcr p15, 0, r0, c1, c0, 0 \n" |
| : |
| : |
| : "r0", "r1" |
| ); |
| } |
| |
| |
| /** Sets the address of level 0 page table. |
| * \param pt pointer to the page table to set |
| */ |
| static inline void set_ptl0_address( pte_level0_section* pt) { |
| static inline void set_ptl0_address(pte_level0_section* pt) |
| { |
| asm volatile ( "mcr p15, 0, %0, c2, c0, 0 \n" |
| : |
| : "r"(pt) |
| : |
| : "r"(pt) |
| ); |
| |
| } |
| |
| /** Page table that holds 1:1 mapping for booting the kernel. */ |
| extern pte_level0_section page_table[PTL0_ENTRIES_ARCH]; |
| |
| /** Sets memory mapping for kernel */ |
| void mm_kernel_mapping(void); |
| |
| #endif |
| |
| #endif |