diff options
Diffstat (limited to 'demo_functionality.c')
| -rw-r--r-- | demo_functionality.c | 96 |
1 files changed, 22 insertions, 74 deletions
diff --git a/demo_functionality.c b/demo_functionality.c index fbf5eb4..7bba6a6 100644 --- a/demo_functionality.c +++ b/demo_functionality.c @@ -2,7 +2,6 @@ #include "psr.h" #include "memory.h" #include "translation_table_descriptors.h" -#include "libkernel.h" void demo_paging_support(void) { @@ -56,73 +55,35 @@ 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_setup_PL0(void) +void demo_go_unprivileged(void) { - short_section_descriptor_t volatile *PL0_section_entry = - &TRANSLATION_TABLE[PL0_SECTION_NUMBER]; - short_section_descriptor_t volatile *UART_memory_section_entry = - &TRANSLATION_TABLE[((uint32_t) GPIO_BASE) >> 20]; + short_section_descriptor_t *translation_table = + (short_section_descriptor_t*) TRANSLATION_TABLE_BASE; - short_section_descriptor_t - PL0_section = *PL0_section_entry, - UART_memory_section = *UART_memory_section_entry; + volatile short_section_descriptor_t *PL0_section = + &translation_table[PL0_SECTION_NUMBER]; + volatile short_section_descriptor_t *UART_memory_section = + &translation_table[((uint32_t) GPIO_BASE) >> 20]; - // set up address of PL0 section - PL0_section.SECTION_BASE_ADDRESS_31_20 = + PL0_section->SECTION_BASE_ADDRESS_31_20 = UNPRIVILEGED_MEMORY_START >> 20; // make the selected section and uart section available for PL0 - PL0_section.ACCESS_PERMISSIONS_2 = + PL0_section->ACCESS_PERMISSIONS_2 = AP_2_0_MODEL_RW_ALL >> 2; - PL0_section.ACCESS_PERMISSIONS_1_0 = + PL0_section->ACCESS_PERMISSIONS_1_0 = AP_2_0_MODEL_RW_ALL & 0b011; - UART_memory_section.ACCESS_PERMISSIONS_2 = + UART_memory_section->ACCESS_PERMISSIONS_2 = AP_2_0_MODEL_RW_ALL >> 2; - UART_memory_section.ACCESS_PERMISSIONS_1_0 = + UART_memory_section->ACCESS_PERMISSIONS_1_0 = AP_2_0_MODEL_RW_ALL & 0b011; - - *PL0_section_entry = PL0_section; - *UART_memory_section_entry = UART_memory_section; + // invalidate main Translation Lookup Buffer (just in case) asm("mcr p15, 0, %0, c8, c7, 0\n\r" @@ -138,30 +99,17 @@ void demo_setup_PL0(void) uart_puts((char*) VIRTUAL_PL0_MEMORY_START); - // now paste a userspace program to that section + // now paste a userspace program to that section, jump to it and + // switch to PL0 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; - - void *call_unprivileged_new_location = - (void*) (LIBKERNEL_SECTION_START + call_unprivileged_offset); - - // call call_unprivileged from libkernel - asm volatile("mov r5, %0\n\r" - "mov r0, %1\n\r" - "mov r4, #0\n\r" - "movt r4, #"PL0_SECTION_NUMBER_STR"1111\n\r" - "mov sp, r4\n\r" // setting stack is important :D - "blx r5\n\r" :: - "r" (call_unprivileged_new_location), - "r" (VIRTUAL_PL0_MEMORY_START) - : "memory", "r4", "r5", "r0"); + // jump to that copied code (switch to PL0 is done by that code) + asm volatile("mov r5, #0\n\r" + "movt r5, #"PL0_SECTION_NUMBER_STR"1111\n\r" + "mov sp, r5\n\r" // setting stack is important :D + "mov r5, #0\n\r" + "movt r5, #"PL0_SECTION_NUMBER_STR"0000\n\r" + "blx r5\n\r"); } |