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Merge pull request #50 from SuperHouse/fix/interrupts

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Fix/interrupts
This commit is contained in:
Angus Gratton 2015-10-06 18:36:03 +11:00
commit 5c4cbf69cf
11 changed files with 200 additions and 216 deletions
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16
.dir-locals.el
View file

@ -6,4 +6,20 @@
(c-file-style . "bsd")
(c-basic-offset . 4)
)
(asm-mode
(indent-tabs-mode . nil)
; this is basically a hack so asm-mode indents with spaces not tabs
; taken from http://stackoverflow.com/questions/2668563/emacs-indentation-in-asm-mode
; (moving to gas-mode may be a better choice)
(tab-stop-list (quote (4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112 116 120)))
(asm-comment-char . "#")
)
)
; IMPORTANT: If you want to write assembly and have indenting to not be infuriating,
; you probably also want this in your .emacs file:
;
; (add-hook 'asm-mode-hook '(lambda () (setq indent-line-function 'indent-relative)))
;
; This is not safe to set as a local variable.

59
FreeRTOS/Source/portable/esp8266/port.c
View file

@ -198,6 +198,8 @@ portBASE_TYPE xPortStartScheduler( void )
}
/* Initialize system tick timer interrupt and schedule the first tick. */
_xt_isr_attach(INUM_TICK, sdk__xt_timer_int);
_xt_isr_unmask(BIT(INUM_TICK));
sdk__xt_tick_timer_init();
vTaskSwitchContext();
@ -265,60 +267,3 @@ void IRAM vPortExitCritical( void )
portENABLE_INTERRUPTS();
}
/*-----------------------------------------------------------*/
/* Main ISR handler for FreeRTOS side of the ESP libs?
As far as I can tell, the "real" Xtensa ISRs ("Exceptions") are
handled in libmain.a (xtensa_vectors.o) which then can call into here
passing an interrupt mask.
*/
_xt_isr isr[16];
void IRAM _xt_isr_attach(uint8_t i, _xt_isr func)
{
isr[i] = func;
}
uint16_t IRAM _xt_isr_handler(uint16_t i)
{
uint8_t index;
/* I think this is implementing some kind of interrupt priority or
short-circuiting an expensive ffs for most common interrupts - ie
WDT And GPIO are common or high priority, then remaining flags.
*/
if (i & (1 << INUM_WDT)) {
index = INUM_WDT;
}
else if (i & (1 << INUM_GPIO)) {
index = INUM_GPIO;
}else {
index = __builtin_ffs(i) - 1;
if (index == INUM_MAX) {
/* I don't understand what happens here. INUM_MAX is not
the highest interrupt number listed (and the isr array
has 16 entries).
Clearing that flag and then setting index to
__builtin_ffs(i)-1 may result in index == 255 if no
higher flags are set, unless this is guarded against
somehow by the caller?
I also don't understand why the code is written like
this in esp_iot_rtos_sdk instead of just putting the i
&= line near the top... Probably no good reason?
*/
i &= ~(1 << INUM_MAX);
index = __builtin_ffs(i) - 1;
}
}
_xt_clear_ints(1<<index);
isr[index]();
return i & ~(1 << index);
}

2
FreeRTOS/Source/portable/esp8266/portmacro.h
View file

@ -74,7 +74,7 @@ extern "C" {
#include "espressif/esp8266/ets_sys.h"
#include <stdint.h>
#include "xtensa_rtos.h"
#include "xtensa_interrupts.h"
#include <esp/interrupts.h>
/*-----------------------------------------------------------
* Port specific definitions for ESP8266

12
README.md
View file

@ -134,7 +134,17 @@ The best way to write suitable code is to first add documentation somewhere like
## Coding Style
For new contributions, please use BSD style and indent using 4 spaces. If you're an emacs user then there is a .dir-locals.el file in the root which configures cc-mode.
For new contributions in C, please use BSD style and indent using 4 spaces.
For assembly, please use the following:
* Instructions indented using 8 spaces.
* Inline comments use `#` as a comment delimiter.
* Comments on their own line(s) use `/*`..`*/`.
* First operand of each instruction should be vertically aligned where possible.
* For xtensa special registers, prefer `wsr aX, SR` over `wsr.SR aX`
If you're an emacs user then there is a .dir-locals.el file in the root which configures cc-mode and asm-mode (you will need to approve some variable values as safe). See also
the additional comments in .dir-locals.el, if you're editing assembly code.
Upstream code is left with the indentation and style of the upstream project.

39
core/esp_interrupts.c Normal file
View file

@ -0,0 +1,39 @@
/* ESP8266 Xtensa interrupt management functions
*
*
* Part of esp-open-rtos
* Copyright (C) 2015 Angus Gratton
* BSD Licensed as described in the file LICENSE
*/
#include <esp/interrupts.h>
_xt_isr isr[16];
void IRAM _xt_isr_attach(uint8_t i, _xt_isr func)
{
isr[i] = func;
}
/* Generic ISR handler.
Handles all flags set for interrupts in 'intset'.
*/
uint16_t IRAM _xt_isr_handler(uint16_t intset)
{
/* WDT has highest priority (occasional WDT resets otherwise) */
if(intset & BIT(INUM_WDT)) {
_xt_clear_ints(BIT(INUM_WDT));
isr[INUM_WDT]();
intset -= BIT(INUM_WDT);
}
while(intset) {
uint8_t index = __builtin_ffs(intset) - 1;
uint16_t mask = BIT(index);
_xt_clear_ints(mask);
isr[index]();
intset -= mask;
}
return 0;
}

223
core/exception_vectors.S
View file

@ -25,12 +25,19 @@
.section .bss
NMIHandlerStack: # stack space for NMI handler
.skip 4*0x100
.LNMIHandlerStackTop:
NMIRegisterSaved: # register space for saving NMI registers
.skip 4*(16 + 6)
/* Stack space for NMI handler
NMI handler stack high water mark measured at 0x134 bytes. Any use
of the NMI timer callback will add stack overhead as well.
The NMI handler does a basic check for stack overflow
*/
.balign 16
NMIHandlerStack:
.skip 0x200
.NMIHandlerStackTop:
.balign 16
LoadStoreErrorHandlerStack:
.word 0 # a0
.word 0 # (unused)
@ -67,10 +74,7 @@ DebugExceptionVector:
.org VecBase + 0x20
NMIExceptionVector:
.type NMIExceptionVector, @function
wsr a0, excsave3
call0 CallNMIExceptionHandler
rfi 3 # Should never be reached
j NMIExceptionHandler
.org VecBase + 0x30
KernelExceptionVector:
@ -371,96 +375,103 @@ call_user_start:
/*************************** NMI Exception Handler ***************************/
#define NMI_STACK_CANARY 0xABBABABA
.section .vecbase.text, "x"
/* Save register relative to a0 */
.macro SAVE_REG register, regnum
s32i \register, a0, (4 * (\regnum + 6))
.endm
/* Load register relative to sp */
.macro LOAD_REG register, regnum
l32i \register, sp, (4 * (\regnum + 6))
.endm
.literal_position
.balign 16
CallNMIExceptionHandler:
.type CallNMIExceptionHandler, @function
NMIExceptionHandler:
.type NMIExceptionHandler, @function
movi a0, NMIRegisterSaved
SAVE_REG a2, 2
SAVE_REG sp, 1
SAVE_REG a3, 3
rsr a2, excsave3 # a2 is now former a0
SAVE_REG a4, 4
SAVE_REG a2, 0
rsr a3, epc1
rsr a4, exccause
SAVE_REG a3, -5
SAVE_REG a4, -4
rsr a3, excvaddr
SAVE_REG a3, -3
rsr a3, excsave1
SAVE_REG a3, -2
SAVE_REG a5, 5
SAVE_REG a6, 6
SAVE_REG a7, 7
SAVE_REG a8, 8
SAVE_REG a9, 9
SAVE_REG a10, 10
SAVE_REG a11, 11
SAVE_REG a12, 12
SAVE_REG a13, 13
SAVE_REG a14, 14
SAVE_REG a15, 15
movi sp, .LNMIHandlerStackTop
movi a0, 0
movi a2, 0x23 # argument for handler
wsr a2, ps
wsr sp, excsave3 # excsave3 holds user stack
movi sp, .NMIHandlerStackTop - 0x40
s32i a0, sp, 0x00
s32i a2, sp, 0x04
s32i a3, sp, 0x08
s32i a4, sp, 0x0c
s32i a5, sp, 0x10
s32i a6, sp, 0x14
s32i a7, sp, 0x18
s32i a8, sp, 0x1c
s32i a9, sp, 0x20
s32i a10, sp, 0x24
s32i a11, sp, 0x28
rsr a0, epc1
s32i a0, sp, 0x2c
rsr a0, exccause
s32i a0, sp, 0x30
rsr a0, excsave1
s32i a0, sp, 0x34
rsr a0, excvaddr
s32i a0, sp, 0x38
rsr a0, sar
s32i a0, sp, 0x3c
movi a0, 0x23 # Override PS for NMI handler
wsr a0, ps
rsync
rsr a14, sar
s32i a14, sp, 0 # this is also NMIRegisterSaved+0
/* mark the stack overflow point before we call the actual NMI handler */
movi a0, NMIHandlerStack
movi a2, NMI_STACK_CANARY
s32i a2, a0, 0x00
call0 sdk_wDev_ProcessFiq
l32i a15, sp, 0
wsr a15, sar
movi a2, 0x33
wsr a2, ps
/* verify we didn't overflow */
movi a0, NMIHandlerStack
l32i a3, a0, 0
movi a2, NMI_STACK_CANARY
bne a3, a2, .NMIFatalStackOverflow
l32i a0, sp, 0x3c
wsr a0, sar
l32i a0, sp, 0x38
wsr a0, excvaddr
l32i a0, sp, 0x34
wsr a0, excsave1
l32i a0, sp, 0x30
wsr a0, exccause
l32i a0, sp, 0x2c
wsr a0, epc1
l32i a11, sp, 0x28
l32i a10, sp, 0x24
l32i a9, sp, 0x20
l32i a8, sp, 0x1c
l32i a7, sp, 0x18
l32i a6, sp, 0x14
l32i a5, sp, 0x10
l32i a4, sp, 0x0c
l32i a3, sp, 0x08
movi a0, 0x33 # Reset PS
wsr a0, ps
rsync
LOAD_REG a4, 4
LOAD_REG a5, 5
LOAD_REG a6, 6
LOAD_REG a7, 7
LOAD_REG a8, 8
LOAD_REG a9, 9
LOAD_REG a10, 10
LOAD_REG a11, 11
LOAD_REG a12, 12
LOAD_REG a13, 13
LOAD_REG a14, 14
LOAD_REG a15, 15
LOAD_REG a2, -5
LOAD_REG a3, -4
wsr a2, epc1
wsr a3, exccause
LOAD_REG a2, -3
LOAD_REG a3, -2
wsr a2, excvaddr
wsr a3, excsave1
LOAD_REG a0, 0
/* set dport nmi status bit 0 (wDev_ProcessFiq clears & verifies this
* bit stays cleared, see
/* set dport nmi status to 1 (wDev_ProcessFiq clears bit 0 and verifies it
* stays cleared, see
* http://esp8266-re.foogod.com/wiki/WDev_ProcessFiq_%28IoT_RTOS_SDK_0.9.9%29)
*/
movi a2, 0x3ff00000
movi a3, 0x1
s32i a3, a2, 0
LOAD_REG a2, 2
LOAD_REG a3, 3
LOAD_REG a1, 1
movi a0, 0x3ff00000
movi a2, 0x1
s32i a2, a0, 0
l32i a2, sp, 0x04
l32i a0, sp, 0x00
movi a1, 0x0
xsr a1, excsave3 # Load stack back from excsave3, clear excsave3
rfi 3
.section .rodata
.NMIStackOverflowErrorMsg:
.string "\nFATAL: NMI Stack Overflow\n"
.section .vecbase.text, "x"
.NMIFatalStackOverflow:
movi a2, .NMIStackOverflowErrorMsg
call0 printf
.NMIInfiniteLoop:
j .NMIInfiniteLoop /* TODO: replace with call to abort() */
/*********************** General UserException Handler ***********************/
.section .vecbase.text, "x"
@ -469,7 +480,6 @@ CallNMIExceptionHandler:
* LoadStoreCause. */
.literal_position
.balign 4
UserExceptionHandler:
.type UserExceptionHandler, @function
@ -490,46 +500,28 @@ UserExceptionHandler:
wsr a0, ps
rsync
rsr a2, exccause
beqi a2, CAUSE_LVL1INT, UserHandleInterrupt
/* Any UserException cause other than level 1 interrupt should panic */
UserFailOtherExceptionCause:
break 1, 1
call0 sdk_user_fatal_exception_handler
UserHandleInterrupt:
/* Any UserException cause other than a level 1 interrupt is fatal */
bnei a2, CAUSE_LVL1INT, .LUserFailOtherExceptionCause
.LUserHandleInterrupt:
rsil a0, 1
rsr a2, intenable
rsr a3, interrupt
movi a4, 0x3fff
and a2, a2, a3
and a2, a2, a4 # a2 = 0x3FFF & INTENABLE & INTERRUPT
UserHandleTimer:
movi a3, 0xffbf
and a3, a2, a3 # a3 = a2 with bit 6 cleared
bnez a3, UserTimerDone # If any non-timer interrupt bits set
movi a3, 0x40
sub a12, a2, a3 # a12 = a2 - 0x40 -- Will be zero if bit 6 set
call0 sdk__xt_timer_int # tick timer interrupt
mov a2, a12 # restore a2 from a12, ie zero
beqz a2, UserIntDone
UserTimerDone:
call0 _xt_isr_handler
bnez a2, UserHandleTimer
UserIntDone:
beqz a2, UserIntExit
/* FIXME: this code will never be reached */
call0 sdk__xt_int_exit # once finished, jumps to _xt_user_exit via stack
.literal_position
.LUserFailOtherExceptionCause:
break 1, 1
call0 sdk_user_fatal_exception_handler
UserIntExit:
call0 sdk__xt_int_exit # jumps to _xt_user_exit. Never returns here
.section .text
/* _xt_user_exit is used to exit interrupt context. */
/* TODO: Find a better place for this to live. */
/* _xt_user_exit is pushed onto the stack as part of the user exception handler,
restores same set registers which were saved there and returns from exception */
_xt_user_exit:
.global _xt_user_exit
.type _xt_user_exit, @function
l32i a0, sp, 0x8
wsr a0, ps
l32i a0, sp, 0x4
@ -538,4 +530,3 @@ _xt_user_exit:
l32i sp, sp, 0x10
rsync
rfe

33
core/include/esp/cpu.h
View file

@ -1,33 +0,0 @@
/* esp/cpu.h
*
* Details relating to the ESP8266 Xtensa core.
*
*/
#ifndef _ESP_CPU_H
#define _ESP_CPU_H
#include <stdbool.h>
/* Interrupt numbers for level 1 exception handler.
*
* Currently the UserExceptionVector calls down to _xt_isr_handler,
* defined in port.c, for at least some of these interrupts. Some are handled
* on the SDK side, though.
*/
typedef enum {
INUM_SPI = 2,
INUM_GPIO = 4,
INUM_UART = 5,
INUM_MAX = 6, /* in some places this is documented as timer0 CCOMPARE0 interrupt */
INUM_SOFT = 7,
INUM_WDT = 8,
INUM_TIMER_FRC1 = 9,
/* FRC2 default handler. Configured by sdk_ets_timer_init, which
runs as part of default libmain.a startup code, assigns
interrupt handler to sdk_vApplicationTickHook+0x68
*/
INUM_TIMER_FRC2 = 10,
} xt_isr_num_t;
#endif

3
core/include/esp/gpio.h
View file

@ -11,8 +11,7 @@
#include <stdbool.h>
#include "esp/gpio_regs.h"
#include "esp/iomux.h"
#include "esp/cpu.h"
#include "xtensa_interrupts.h"
#include "esp/interrupts.h"
typedef enum {
GPIO_INPUT,

20
include/xtensa_interrupts.h → core/include/esp/interrupts.h
View file

@ -1,4 +1,4 @@
/* Xtensa interrupt management functions
/* ESP8266 Xtensa interrupt management functions
*
* Some (w/ sdk_ prefix) are implemented in binary libs, rest are
* inlines replacing functions in the binary libraries.
@ -15,9 +15,27 @@
#include <xtensa/hal.h>
#include <common_macros.h>
/* Interrupt numbers for level 1 exception handler. */
typedef enum {
INUM_SPI = 2,
INUM_GPIO = 4,
INUM_UART = 5,
INUM_TICK = 6, /* RTOS timer tick, possibly xtensa CPU CCOMPARE0(?) */
INUM_SOFT = 7,
INUM_WDT = 8,
INUM_TIMER_FRC1 = 9,
/* FRC2 default handler. Configured by sdk_ets_timer_init, which
runs as part of default libmain.a startup code, assigns
interrupt handler to sdk_vApplicationTickHook+0x68
*/
INUM_TIMER_FRC2 = 10,
} xt_isr_num_t;
void sdk__xt_int_exit (void);
void _xt_user_exit (void);
void sdk__xt_tick_timer_init (void);
void sdk__xt_timer_int(void);
void sdk__xt_timer_int1(void);
INLINED uint32_t _xt_get_intlevel(void)

3
core/include/esp/timer.h
View file

@ -10,9 +10,8 @@
#define _ESP_TIMER_H
#include <stdbool.h>
#include <xtensa_interrupts.h>
#include "esp/timer_regs.h"
#include "esp/cpu.h"
#include "esp/interrupts.h"
#ifdef __cplusplus
extern "C" {

2
core/include/esp8266.h
View file

@ -13,7 +13,7 @@
#include "common_macros.h"
#include "esp/registers.h"
#include "esp/cpu.h"
#include "esp/interrupts.h"
#include "esp/iomux.h"
#include "esp/gpio.h"
#include "esp/timer.h"