diff options
| -rw-r--r-- | demo_functionality.c | 59 | ||||
| -rw-r--r-- | demo_functionality.h | 4 | ||||
| -rw-r--r-- | kernel.c | 6 | ||||
| -rw-r--r-- | memory.h | 4 |
4 files changed, 48 insertions, 25 deletions
diff --git a/demo_functionality.c b/demo_functionality.c index 753a7d3..fbf5eb4 100644 --- a/demo_functionality.c +++ b/demo_functionality.c @@ -56,40 +56,56 @@ void demo_mode_to_system(void) set_system_mode(); } +#define TRANSLATION_TABLE \ + ((short_section_descriptor_t volatile*) TRANSLATION_TABLE_BASE) + extern char __renamed_start, __renamed_end, __renamed_size; +void demo_setup_libkernel(void) { + short_section_descriptor_t volatile *libkernel_section_entry = + &TRANSLATION_TABLE[LIBKERNEL_SECTION_NUMBER]; + + short_section_descriptor_t + libkernel_section = *libkernel_section_entry; + + // make libkernel section executable and read-only for + // unprivileged code + libkernel_section.ACCESS_PERMISSIONS_2 = + AP_2_0_MODEL_RW_PL1_RO_PL0 >> 2; + libkernel_section.ACCESS_PERMISSIONS_1_0 = + AP_2_0_MODEL_RW_PL1_RO_PL0 & 0b011; + + *libkernel_section_entry = libkernel_section; + + // invalidate main Translation Lookup Buffer (just in case) + asm("mcr p15, 0, %0, c8, c7, 0\n\r" + "isb" :: "r" (0) : "memory"); + + // copy libkernel code to libkernel section + for (size_t i = 0; i < (size_t) &__renamed_size; i++) + ((volatile char*) LIBKERNEL_SECTION_START)[i] = + (&__renamed_start)[i]; +} + extern char _binary_PL_0_test_img_start, _binary_PL_0_test_img_end, _binary_PL_0_test_img_size; -void demo_go_unprivileged(void) +void demo_setup_PL0(void) { - short_section_descriptor_t *translation_table = - (short_section_descriptor_t*) TRANSLATION_TABLE_BASE; - - short_section_descriptor_t volatile *libkernel_section_entry = - &translation_table[LIBKERNEL_SECTION_NUMBER]; short_section_descriptor_t volatile *PL0_section_entry = - &translation_table[PL0_SECTION_NUMBER]; + &TRANSLATION_TABLE[PL0_SECTION_NUMBER]; short_section_descriptor_t volatile *UART_memory_section_entry = - &translation_table[((uint32_t) GPIO_BASE) >> 20]; + &TRANSLATION_TABLE[((uint32_t) GPIO_BASE) >> 20]; short_section_descriptor_t - libkernel_section = *libkernel_section_entry, PL0_section = *PL0_section_entry, UART_memory_section = *UART_memory_section_entry; - // make libkernel section executable and read-only for - // unprivileged code - libkernel_section.ACCESS_PERMISSIONS_2 = - AP_2_0_MODEL_RW_PL1_RO_PL0 >> 2; - libkernel_section.ACCESS_PERMISSIONS_1_0 = - AP_2_0_MODEL_RW_PL1_RO_PL0 & 0b011; - // set up address of PL0 section PL0_section.SECTION_BASE_ADDRESS_31_20 = UNPRIVILEGED_MEMORY_START >> 20; @@ -105,7 +121,6 @@ void demo_go_unprivileged(void) UART_memory_section.ACCESS_PERMISSIONS_1_0 = AP_2_0_MODEL_RW_ALL & 0b011; - *libkernel_section_entry = libkernel_section; *PL0_section_entry = PL0_section; *UART_memory_section_entry = UART_memory_section; @@ -123,18 +138,16 @@ void demo_go_unprivileged(void) uart_puts((char*) VIRTUAL_PL0_MEMORY_START); - // copy libkernel code to libkernel section - for (size_t i = 0; i < (size_t) &__renamed_size; i++) - ((volatile char*) LIBKERNEL_SECTION_START)[i] = - (&__renamed_start)[i]; - // now paste a userspace program to that section for (size_t i = 0; i < (size_t) &_binary_PL_0_test_img_size; i++) ((volatile char*) VIRTUAL_PL0_MEMORY_START)[i] = (&_binary_PL_0_test_img_start)[i]; uart_puts("copied PL0 and libkernel code to their sections"); - +} + +void demo_go_unprivileged(void) +{ size_t call_unprivileged_offset = (size_t) &call_unprivileged - (size_t) &__renamed_start; diff --git a/demo_functionality.h b/demo_functionality.h index c8b163f..5d6e659 100644 --- a/demo_functionality.h +++ b/demo_functionality.h @@ -5,6 +5,10 @@ void demo_paging_support(void); void demo_mode_to_system(void); +void demo_setup_libkernel(void); + +void demo_setup_PL0(void); + void demo_go_unprivileged(void); #endif // DEMO_FUNCTIONALITY_H @@ -27,6 +27,12 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) // prints some info and sets upp translation table, turns on MMU setup_flat_map(); + demo_setup_libkernel(); + + demo_setup_PL0(); + + demo_go_unprivileged(); + // prints some info and sets up a section for PL0 code, loads a blob // there and jumps to it... never, ever, ever returns demo_go_unprivileged(); @@ -10,8 +10,8 @@ #define STACK_START ((uint32_t) 0x4000) #define STACK_END ((uint32_t) 0x8000) -extern char __end; -extern char __start; +extern const char __end; +extern const char __start; #define KERNEL_START ((uint32_t) &__start) #define KERNEL_END ((uint32_t) &__end) |