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Diffstat (limited to 'c/src/lib/libbsp/lm32/shared/gdbstub/README')
-rw-r--r-- | c/src/lib/libbsp/lm32/shared/gdbstub/README | 82 |
1 files changed, 0 insertions, 82 deletions
diff --git a/c/src/lib/libbsp/lm32/shared/gdbstub/README b/c/src/lib/libbsp/lm32/shared/gdbstub/README deleted file mode 100644 index bbd1f53a9d..0000000000 --- a/c/src/lib/libbsp/lm32/shared/gdbstub/README +++ /dev/null @@ -1,82 +0,0 @@ -This is a thread-aware gdb stub for the lm32 architecture. It has to be -linked with the application, which should be debugged. The application has -to call 'lm32_gdb_stub_install' to setup the stub. - The stub remaps _all_ h/w exceptions to an own code (lm32-debug.S), which -saves all the registers, calls the gdb stub and restores the registers again. - The interrupt exceptions gets handled in a special way. Because we remapped -this exception, we need to do - - the same as the original one (in cpu_asm.S), - - and, as we might use an ISR for breaking into a running application with - gdb, we need to save all registers as well. To be backward compatible - the missing callee saved registers gets appended to CPU_Interrupt_frame. - There is a mapping in 'gdb_handle_break' for that. - -To use this gdb stub, your bsp has to provide the following functions: - - void gdb_put_debug_char(char c) - Puts the given charater c to the debug console output. The function can - block until the character can be written to the output buffer. - - - char gdb_get_debug_char(void) - Returns the character in the input buffer of the debug console. If no one - is availabe, the function must block. - - - void gdb_console_init() - This function can be used to initialize the debug console. Additionally, - it should set up the ISR for the debug console to call the function - 'gdb_handle_break', which is provided by the gdb stub and enable the - interrupt for a break symbol on the debug serial port. If no ISR is - provided, you won't be able to interrupt a running application. - - - void gdb_ack_irq() - If an ISR is used, this function is used to acknowledge the interrupt. - -NOTE: the stub don't skip a hardcoded 'break' in the code. So you have to - set the PC an instruction further in the debugger (set $pc += 4). - -NOTE2: make sure you have the following CFLAGS set: - -mbarrel-shift-enabled -mmultiply-enabled -mdivide-enabled - -msign-extend-enabled - Without the hardware support, it is done in software. Unfortunately, the - stub also uses some shifts and multiplies. If you step through your code, - there will be a chance that a breakpoint is set to one of that functions, - which then causes an endless loop. - - -EXAMPLES - - char gdb_get_debug_char(void) - { - /* Wait until there is a byte in RXTX */ - while (!(uartread(LM32_UART_LSR) & LM32_UART_LSR_DR)); - - return (char) uartread(LM32_UART_RBR); - } - - void gdb_put_debug_char(char c) - { - /* Wait until RXTX is empty. */ - while (!(uartread(LM32_UART_LSR) & LM32_UART_LSR_THRE)); - uartwrite(LM32_UART_RBR, c); - } - - extern void gdb_handle_break( - rtems_vector_number vector, - CPU_Interrupt_frame *frame - ); - void gdb_console_init() - { - rtems_isr_entry old; - - /* enable interrupts */ - uartwrite(LM32_UART_IER, 1); - - rtems_interrupt_catch((rtems_isr_entry) gdb_handle_break, DEBUG_UART_IRQ, - &old); - lm32_interrupt_unmask(1 << DEBUG_UART_IRQ); - } - - void gdb_ack_irq() - { - lm32_interrupt_ack(1 << DEBUG_UART_IRQ); - } - |