diff --git a/cores/esp8266/core_esp8266_postmortem.cpp b/cores/esp8266/core_esp8266_postmortem.cpp index bd69748815..50bafa6eba 100644 --- a/cores/esp8266/core_esp8266_postmortem.cpp +++ b/cores/esp8266/core_esp8266_postmortem.cpp @@ -110,10 +110,26 @@ static void cut_here() { ets_putc('\n'); } -void __wrap_system_restart_local() { - register uint32_t sp asm("a1"); - uint32_t sp_dump = sp; - +/* + Add some assembly to grab the stack pointer and pass it as an argument before + it grows for the target function. Should stabilize the stack offsets, used to + find the relevant stack content for dumping. +*/ +extern "C" void __wrap_system_restart_local(void); +asm( + ".section .text.__wrap_system_restart_local,\"ax\",@progbits\n\t" + ".literal_position\n\t" + ".align 4\n\t" + ".global __wrap_system_restart_local\n\t" + ".type __wrap_system_restart_local, @function\n\t" + "\n" +"__wrap_system_restart_local:\n\t" + "mov a2, a1\n\t" + "j postmortem_report\n\t" + ".size __wrap_system_restart_local, .-__wrap_system_restart_local\n\t" +); + +static void postmortem_report(uint32_t sp_dump) { struct rst_info rst_info; memset(&rst_info, 0, sizeof(rst_info)); if (s_user_reset_reason == REASON_DEFAULT_RST) @@ -152,9 +168,17 @@ void __wrap_system_restart_local() { else if (rst_info.reason == REASON_EXCEPTION_RST) { // The GCC divide routine in ROM jumps to the address below and executes ILL (00 00 00) on div-by-zero // In that case, print the exception as (6) which is IntegerDivZero - bool div_zero = (rst_info.exccause == 0) && (rst_info.epc1 == 0x4000dce5); + uint32_t epc1 = rst_info.epc1; + uint32_t exccause = rst_info.exccause; + bool div_zero = (exccause == 0) && (epc1 == 0x4000dce5u); + if (div_zero) { + exccause = 6; + // In place of the detached 'ILL' instruction., redirect attention + // back to the code that called the ROM divide function. + __asm__ __volatile__("rsr.excsave1 %0\n\t" : "=r"(epc1) :: "memory"); + } ets_printf_P(PSTR("\nException (%d):\nepc1=0x%08x epc2=0x%08x epc3=0x%08x excvaddr=0x%08x depc=0x%08x\n"), - div_zero ? 6 : rst_info.exccause, rst_info.epc1, rst_info.epc2, rst_info.epc3, rst_info.excvaddr, rst_info.depc); + exccause, epc1, rst_info.epc2, rst_info.epc3, rst_info.excvaddr, rst_info.depc); } else if (rst_info.reason == REASON_SOFT_WDT_RST) { ets_printf_P(PSTR("\nSoft WDT reset\n")); @@ -174,16 +198,31 @@ void __wrap_system_restart_local() { // amount of stack taken by interrupt or exception handler // and everything up to __wrap_system_restart_local - // (determined empirically, might break) + // ~(determined empirically, might break)~ uint32_t offset = 0; if (rst_info.reason == REASON_SOFT_WDT_RST) { - offset = 0x1a0; + // Stack Tally + // 256 User Exception vector handler reserves stack space + // directed to _xtos_l1int_handler function in Boot ROM + // 48 wDev_ProcessFiq - its address appears in a vector table at 0x3FFFC27C + // 16 ?unnamed? - index into a table, pull out pointer, and call if non-zero + // appears near near wDev_ProcessFiq + // 32 pp_soft_wdt_feed_local - gather the specifics and call __wrap_system_restart_local + offset = 32 + 16 + 48 + 256; } else if (rst_info.reason == REASON_EXCEPTION_RST) { - offset = 0x190; + // Stack Tally + // 256 Exception vector reserves stack space + // filled in by "C" wrapper handler + // 16 Handler level 1 - enable icache + // 64 Handler level 2 - exception report + offset = 64 + 16 + 256; } else if (rst_info.reason == REASON_WDT_RST) { - offset = 0x10; + offset = 16; + } + else if (rst_info.reason == REASON_USER_SWEXCEPTION_RST) { + offset = 16; } ets_printf_P(PSTR("\n>>>stack>>>\n")); @@ -280,8 +319,9 @@ static void raise_exception() { s_user_reset_reason = REASON_USER_SWEXCEPTION_RST; ets_printf_P(PSTR("\nUser exception (panic/abort/assert)")); - __wrap_system_restart_local(); - + uint32_t sp; + __asm__ __volatile__ ("mov %0, a1\n\t" : "=r"(sp) :: "memory"); + postmortem_report(sp); while (1); // never reached, needed to satisfy "noreturn" attribute } @@ -321,7 +361,9 @@ void __stack_chk_fail(void) { if (gdb_present()) __asm__ __volatile__ ("syscall"); // triggers GDB when enabled - __wrap_system_restart_local(); + uint32_t sp; + __asm__ __volatile__ ("mov %0, a1\n\t" : "=r"(sp) :: "memory"); + postmortem_report(sp); __builtin_unreachable(); // never reached, needed to satisfy "noreturn" attribute }