diff options
| -rw-r--r-- | Makefile | 6 | ||||
| -rw-r--r-- | TODOs | 4 | ||||
| -rw-r--r-- | cpsr.h | 39 | ||||
| -rw-r--r-- | kernel.c | 52 | ||||
| -rw-r--r-- | pipe_image.c | 64 |
5 files changed, 122 insertions, 43 deletions
@@ -1,4 +1,4 @@ -CFLAGS=-mcpu=cortex-a7 -ffreestanding -std=gnu99 -Wall -Wextra -I. +CFLAGS=-mcpu=cortex-a7 -ffreestanding -std=gnu11 -Wall -Wextra -I. ELFFLAGS=-ffreestanding -O2 -nostdlib -lgcc -I. @@ -45,10 +45,10 @@ qemu-elf : kernel.elf qemu-system-arm -m 256 -M raspi2 -serial stdio -kernel $^ qemu-bin : loader.elf kernel7.img pipe_image - ./pipe_image && qemu-system-arm -m 256 -M raspi2 -serial stdio -kernel $< + ./pipe_image --stdout | qemu-system-arm -m 256 -M raspi2 -serial stdio -kernel $< run-on-rpi : kernel7.img pipe_image - ./pipe_image | socat FILE:/dev/ttyUSB0,b115200,raw - + ./pipe_image --stdout | socat FILE:/dev/ttyUSB0,b115200,raw - sleep 1 screen /dev/ttyUSB0 115200,cs8,-parenb,-cstopb,-hupcl @@ -17,4 +17,6 @@ * Start doing this on hardware already... (Hey, whole making of a bootloader was with this in mind!) -* Find a way to pipe kernel through uart (I'm afraid `./pipe_image | screen ...` might not work)
\ No newline at end of file +* Fix piping with pipe_image + +* write some procedures for dumping registers and other stuff (for use in debugging)
\ No newline at end of file @@ -0,0 +1,39 @@ +#include <stdint.h> + +enum execution_mode { + MODE_USER = 0x10, + MODE_FIQ = 0x11, + MODE_IRQ = 0x12, + MODE_SUPERVISOR = 0x13, + MODE_MONITOR = 0x16, + MODE_ABORT = 0x17, + MODE_HYPERVISOR = 0x1a, + MODE_UNDEFINED = 0x1b, + MODE_SYSTEM = 0x1f, +}; + +inline static uint32_t read_CPSR(void) +{ + uint32_t CPSR; + // get content of current program status register + asm("mrs %0, cpsr" : "=r" (CPSR) ::); + + return CPSR; +} + +inline static enum execution_mode read_processor_mode(void) +{ + /* lowest 5 bits indicate processor mode */ + return read_CPSR() & 0x1f; +} + +inline static void set_system_mode(void) +{ + uint32_t CPSR = read_CPSR(); + + CPSR = (CPSR >> 5) << 5; + + CPSR |= MODE_SYSTEM; + + asm("msr cpsr, %0" :: "r" (CPSR) : "memory"); +} @@ -1,4 +1,5 @@ -#include <uart.h> +#include "uart.h" +#include "cpsr.h" void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) { @@ -20,16 +21,16 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) // uart_puts("Hello, kernel World!\r\n"); char *paging; - - switch(ID_MMFR0 & 0xf) /* lowest 4 bits indicate VMSA support */ { - case 0 : paging = "no paging\n\r"; break; - case 1 : paging = "implementation defined paging\n\r\r\n"; break; - case 2 : paging = "VMSAv6, with cache and TLB type registers\n\r"; break; - case 3 : paging = "VMSAv7, with support for remapping and access flag\n\r"; break; - case 4 : paging = "VMSAv7 with PXN bit supported\n\r"; break; - case 5 : paging = "VMSAv7, PXN and long format descriptors. EPAE is supported.\n\r"; break; - default : paging = "?_? unknown paging ?_?\n\r"; - } + switch(ID_MMFR0 & 0xf) /* lowest 4 bits indicate VMSA support */ + { + case 0 : paging = "no paging\n\r"; break; + case 1 : paging = "implementation defined paging\n\r"; break; + case 2 : paging = "VMSAv6, with cache and TLB type registers\n\r"; break; + case 3 : paging = "VMSAv7, with support for remapping and access flag\n\r"; break; + case 4 : paging = "VMSAv7 with PXN bit supported\n\r"; break; + case 5 : paging = "VMSAv7, PXN and long format descriptors. EPAE is supported.\n\r"; break; + default : paging = "?_? unknown paging ?_?\n\r"; + } uart_puts(paging); @@ -39,19 +40,22 @@ void kernel_main(uint32_t r0, uint32_t r1, uint32_t atags) asm("mrs %0, cpsr" : "=r" (CPSR) :: "memory"); char *mode; - - switch(CPSR & 0x1f) /* lowest 5 bits indicate processor mode */ { - case 0x10 : mode = "User (PL0)\r\n"; break; - case 0x11 : mode = "FIQ (PL1)\r\n"; break; - case 0x12 : mode = "IRQ (PL1)\r\n"; break; - case 0x13 : mode = "Supervisor (PL1)\r\n"; break; - case 0x16 : mode = "Monitor (PL1)\r\n"; break; - case 0x17 : mode = "Abort (PL1)\r\n"; break; - case 0x1a : mode = "Hyp (PL2)\r\n"; break; - case 0x1b : mode = "Undefined (PL1)\r\n"; break; - case 0x1f : mode = "System (PL1)\r\n"; break; - default : mode = "Unknown mode\r\n"; break; - } + + switch(read_processor_mode()) + { + case 0x10 : mode = "User (PL0)\r\n"; break; + case 0x11 : mode = "FIQ (PL1)\r\n"; break; + case 0x12 : mode = "IRQ (PL1)\r\n"; break; + case 0x13 : mode = "Supervisor (PL1)\r\n"; break; + case 0x16 : mode = "Monitor (PL1)\r\n"; break; + case 0x17 : mode = "Abort (PL1)\r\n"; break; + case 0x1a : mode = "Hyp (PL2)\r\n"; break; + case 0x1b : mode = "Undefined (PL1)\r\n"; break; + case 0x1f : mode = "System (PL1)\r\n"; break; + default : mode = "Unknown mode\r\n"; break; + } + + set_system_mode(); uart_puts(mode); diff --git a/pipe_image.c b/pipe_image.c index b52cec2..03d2c8f 100644 --- a/pipe_image.c +++ b/pipe_image.c @@ -6,18 +6,32 @@ #include "lib/rs232/rs232.h" #define ANSI_FG_RED "\033[0;31m" +#define ANSI_FG_DEFAULT "\033[0;39m" -/* This program pipes it's argument file to stdout prepending it */ -/* with it's size (4 bytes, little endian). It is intended to be used */ -/* with our bootloader (i.e. by piping kernel image to UART). */ +/* This program pipes it's argument file to /dev/ttyUSB0 or stdout */ +/* prepending it with it's size (4 bytes, little endian). */ +/* It is intended to be used with our bootloader. */ -int main(int argc, char **argv) { - char *image_file_name = argc > 1 ? argv[1] : "kernel7.img"; +int main(int argc, const char **argv) { + const char *image_file_name = "kernel7.img"; + _Bool stdout_instead_of_uart = 0; + + if (argc > 1) + if (!strcmp(argv[1], "--stdout")) + { + stdout_instead_of_uart = 1; + argc--; + argv++; + } + + if (argc > 1) + image_file_name = argv[1]; FILE *image_file_handle = fopen(image_file_name, "r"); if (!image_file_handle) - err(-1, "couldn't open" ANSI_FG_RED "%s", image_file_name); + err(-1, "couldn't open" ANSI_FG_RED "%s" ANSI_FG_DEFAULT, + image_file_name); if (fseek(image_file_handle, 0, SEEK_END)) err(-1, "error navigating through file"); @@ -33,16 +47,25 @@ int main(int argc, char **argv) { err(-1, "error navigating through file"); //init comport - int comport=16; - - if(RS232_OpenComport(comport,115200,"8N1",0)==1) - err(1,"Error opening comport"); + const int comport=16; + if (!stdout_instead_of_uart) + if (RS232_OpenComport(comport, 115200, "8N1", 0) == 1) + err(-1, "Error opening comport"); uint32_t image_size_le = htole32(image_size); - if (RS232_SendBuf(comport,(unsigned char*)&image_size_le,4) == 1) - err(1, "error writing number to serial"); + if (stdout_instead_of_uart) + { + if (fwrite((unsigned char*) &image_size_le, 4, 1, stdout) != 1) + err(-1, "error writing number to stdout"); + } + else + { + if (RS232_SendBuf(comport, (unsigned char*) &image_size_le, 4) + == 1) + err(-1, "error writing number to serial"); + } ssize_t bytes_left = image_size; @@ -54,10 +77,21 @@ int main(int argc, char **argv) { < 1) err(-1, "error reading the file"); - if (RS232_SendBuf(comport,buf,bytes_read) == 1) - err(1, "error writing to serial"); + if (stdout_instead_of_uart) + { + if (fwrite((unsigned char*) buf, bytes_read, 1, stdout) != 1) + err(-1, "error writing to stdout"); + } + else + { + if (RS232_SendBuf(comport, buf, bytes_read) == 1) + err(-1, "error writing to serial"); + } bytes_left -= bytes_read; } - RS232_CloseComport(comport); + if (!stdout_instead_of_uart) + RS232_CloseComport(comport); + + return 0; } |