diff options
| -rw-r--r-- | PL0_test.ld | 5 | ||||
| -rw-r--r-- | demo_functionality.c | 96 | ||||
| -rw-r--r-- | demo_functionality.h | 4 | ||||
| -rw-r--r-- | interrupts.h | 37 | ||||
| -rw-r--r-- | kernel.c | 2 | ||||
| -rw-r--r-- | memory.h | 28 |
6 files changed, 68 insertions, 104 deletions
diff --git a/PL0_test.ld b/PL0_test.ld index 45bee5e..430e098 100644 --- a/PL0_test.ld +++ b/PL0_test.ld @@ -4,11 +4,6 @@ SECTIONS { /* 0b10101010101000000000000000000000 */ . = 0xaaa00000; - - /* For some reason ld warns when _start is not defined. */ - /* Other .elf files link ok - only PL0_test.elf seems to */ - /* expect _start to be deifned. */ - _start = .; __start = .; __text_start = .; .text : diff --git a/demo_functionality.c b/demo_functionality.c index 60b0bfa..d4b86db 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" @@ -138,32 +99,19 @@ 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"); } extern char diff --git a/demo_functionality.h b/demo_functionality.h index 73a284b..86e7902 100644 --- a/demo_functionality.h +++ b/demo_functionality.h @@ -5,10 +5,6 @@ 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); void demo_setup_interrupts(void); diff --git a/interrupts.h b/interrupts.h new file mode 100644 index 0000000..9dacc42 --- /dev/null +++ b/interrupts.h @@ -0,0 +1,37 @@ +#ifndef RPI_MMU_EXAMPLE_INTERRUPTS_H +#define RPI_MMU_EXAMPLE_INTERRUPTS_H + +#include <stdint.h> + + //offset of peripherals+ offset for first addresable register for interupt controller +#define RPI_INTERRUPT_CONTROLLER_BASE ( 0x3F000000UL + 0xB200 ) + +// Bits in the Enable_Basic_IRQs register to enable various interrupts. +// According to the BCM2835 ARM Peripherals manual, section 7.5 */ + +#define RPI_BASIC_ARM_TIMER_IRQ (1 << 0) +#define RPI_BASIC_ARM_MAILBOX_IRQ (1 << 1) +#define RPI_BASIC_ARM_DOORBELL_0_IRQ (1 << 2) +#define RPI_BASIC_ARM_DOORBELL_1_IRQ (1 << 3) +#define RPI_BASIC_GPU_0_HALTED_IRQ (1 << 4) +#define RPI_BASIC_GPU_1_HALTED_IRQ (1 << 5) +#define RPI_BASIC_ACCESS_ERROR_1_IRQ (1 << 6) +#define RPI_BASIC_ACCESS_ERROR_0_IRQ (1 << 7) + +// @brief The interrupt controller memory mapped register set +typedef struct { + volatile uint32_t IRQ_basic_pending; + volatile uint32_t IRQ_pending_1; + volatile uint32_t IRQ_pending_2; + volatile uint32_t FIQ_control; + volatile uint32_t Enable_IRQs_1; + volatile uint32_t Enable_IRQs_2; + volatile uint32_t Enable_Basic_IRQs; + volatile uint32_t Disable_IRQs_1; + volatile uint32_t Disable_IRQs_2; + volatile uint32_t Disable_Basic_IRQs; +} rpi_irq_controller_t; + +extern rpi_irq_controller_t* RPI_GetIrqController(void); + +#endif //RPI_MMU_EXAMPLE_INTERRUPTS_H @@ -1,6 +1,7 @@ #include "uart.h" #include "demo_functionality.h" #include "paging.h" +#include "interrupts.h" void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) { @@ -18,6 +19,7 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) uart_puts("Hello, kernel World!\r\n"); + enable_interrupt(); // prints some info demo_paging_support(); @@ -1,17 +1,13 @@ #ifndef MEMORY_H #define MEMORY_H -#include "paging.h" - -#define SECTION_SIZE (((uint32_t) 1) << 20) - #define INTERRUPT_VECTOR_TABLE_START ((uint32_t) 0x0) #define STACK_START ((uint32_t) 0x4000) #define STACK_END ((uint32_t) 0x8000) -extern const char __end; -extern const char __start; +extern char __end; +extern char __start; #define KERNEL_START ((uint32_t) &__start) #define KERNEL_END ((uint32_t) &__end) @@ -24,21 +20,11 @@ extern const char __start; #define TRANSLATION_TABLE_END \ (TRANSLATION_TABLE_BASE + (uint32_t) (4096 * 4)) -#define LIBKERNEL_SECTION_START \ - (((TRANSLATION_TABLE_END - (uint32_t) 1) & ~((uint32_t) 0xfffff)) \ - + SECTION_SIZE) - -#define LIBKERNEL_SECTION_END \ - (LIBKERNEL_SECTION_START + SECTION_SIZE) +#define PRIVILEGED_MEMORY_END TRANSLATION_TABLE_END -// section for libkernel is flat-mapped -#define LIBKERNEL_SECTION_NUMBER (LIBKERNEL_SECTION_START >> 20) - -#define PRIVILEGED_MEMORY_END LIBKERNEL_SECTION_END - -#define UNPRIVILEGED_MEMORY_START PRIVILEGED_MEMORY_END -#define UNPRIVILEGED_MEMORY_END \ - (UNPRIVILEGED_MEMORY_START + SECTION_SIZE) +#define UNPRIVILEGED_MEMORY_START \ + (((PRIVILEGED_MEMORY_END - (uint32_t) 1) & ~((uint32_t) 0xfffff)) \ + + (uint32_t) 0x100000) #define PL0_SECTION_NUMBER ((uint32_t) 0b101010101010) #define PL0_SECTION_NUMBER_STR "0b101010101010" @@ -46,4 +32,4 @@ extern const char __start; #define VIRTUAL_PL0_MEMORY_START (PL0_SECTION_NUMBER << 20) #endif // MEMORY_H - + |