diff options
Diffstat (limited to 'projects/cros-ec/patches')
10 files changed, 749 insertions, 0 deletions
diff --git a/projects/cros-ec/patches/nyan/0001-use-_DEFAULT_SOURCE-for-newer-glibc.patch b/projects/cros-ec/patches/nyan/0001-use-_DEFAULT_SOURCE-for-newer-glibc.patch new file mode 100644 index 00000000..ef3d40dc --- /dev/null +++ b/projects/cros-ec/patches/nyan/0001-use-_DEFAULT_SOURCE-for-newer-glibc.patch @@ -0,0 +1,53 @@ +From b98bd2808f4185970781bd4dcca141cbda9b03c6 Mon Sep 17 00:00:00 2001 +From: Mike Frysinger <vapier@chromium.org> +Date: Mon, 7 Dec 2015 21:46:13 -0500 +Subject: [PATCH 1/4] use _DEFAULT_SOURCE for newer glibc + +Newer versions of glibc have moved to _DEFAULT_SOURCE and away from +_BSD_SOURCE. Trying to use the BSD define by itself leads to warnings +which causes build failures. + +BRANCH=none +BUG=None +TEST=precq still works + +Signed-off-by: Mike Frysinger <vapier@chromium.org> +Change-Id: Ice24b84dc6a540695fc7b76e8f22a4c85c301976 +Reviewed-on: https://chromium-review.googlesource.com/316730 +Reviewed-by: Bill Richardson <wfrichar@chromium.org> +--- + util/ec_uartd.c | 3 ++- + util/stm32mon.c | 3 ++- + 2 files changed, 4 insertions(+), 2 deletions(-) + +diff --git a/util/ec_uartd.c b/util/ec_uartd.c +index fbf4a5e..bfd0642 100644 +--- a/util/ec_uartd.c ++++ b/util/ec_uartd.c +@@ -11,7 +11,8 @@ + */ + + /* Force header files to define grantpt(), posix_openpt(), cfmakeraw() */ +-#define _BSD_SOURCE ++#define _DEFAULT_SOURCE /* Newer glibc */ ++#define _BSD_SOURCE /* Older glibc */ + #define _XOPEN_SOURCE 600 + /* Force header file to declare ptsname_r(), etc. */ + #ifndef _GNU_SOURCE +diff --git a/util/stm32mon.c b/util/stm32mon.c +index 2e73bcf..f65cd64 100644 +--- a/util/stm32mon.c ++++ b/util/stm32mon.c +@@ -6,7 +6,8 @@ + */ + + /* use cfmakeraw() */ +-#define _BSD_SOURCE ++#define _DEFAULT_SOURCE /* Newer glibc */ ++#define _BSD_SOURCE /* Older glibc */ + + #include <arpa/inet.h> + #include <errno.h> +-- +2.9.0 + diff --git a/projects/cros-ec/patches/nyan/0002-Enforce-compilation-without-system-headers.patch b/projects/cros-ec/patches/nyan/0002-Enforce-compilation-without-system-headers.patch new file mode 100644 index 00000000..db747ea9 --- /dev/null +++ b/projects/cros-ec/patches/nyan/0002-Enforce-compilation-without-system-headers.patch @@ -0,0 +1,27 @@ +From fd77232c8e9789f5556fc6cc3c694924c1546a41 Mon Sep 17 00:00:00 2001 +From: Paul Kocialkowski <contact@paulk.fr> +Date: Wed, 20 Jul 2016 16:26:32 +0200 +Subject: [PATCH 2/4] Enforce compilation without system headers + +This is based on commit bc404c94b4ab1e6a62e607fd7ef034aa31d6388e +(Enforce compilation without system headers) +--- + Makefile.toolchain | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/Makefile.toolchain b/Makefile.toolchain +index dd0ebb2..47991e1 100644 +--- a/Makefile.toolchain ++++ b/Makefile.toolchain +@@ -19,7 +19,7 @@ BUILDCC?=gcc + HOSTCC?=$(HOST_CROSS_COMPILE)gcc + + CFLAGS_WARN=-Wall -Werror -Wundef -Wstrict-prototypes -Wno-trigraphs \ +- -fno-strict-aliasing -fno-common \ ++ -fno-strict-aliasing -fno-common -ffreestanding -fno-builtin \ + -Werror-implicit-function-declaration -Wno-format-security \ + -fno-delete-null-pointer-checks -Wdeclaration-after-statement \ + -Wno-pointer-sign -fno-strict-overflow -fconserve-stack +-- +2.9.0 + diff --git a/projects/cros-ec/patches/nyan/0003-Don-t-declare-functions-inline-that-aren-t-always-de.patch b/projects/cros-ec/patches/nyan/0003-Don-t-declare-functions-inline-that-aren-t-always-de.patch new file mode 100644 index 00000000..33f714d8 --- /dev/null +++ b/projects/cros-ec/patches/nyan/0003-Don-t-declare-functions-inline-that-aren-t-always-de.patch @@ -0,0 +1,28 @@ +From 9d747549141e710c324968636522e57fe4ba9445 Mon Sep 17 00:00:00 2001 +From: Paul Kocialkowski <contact@paulk.fr> +Date: Wed, 20 Jul 2016 16:27:05 +0200 +Subject: [PATCH 3/4] Don't declare functions inline that aren't always defined + as such + +This is based on commit 960cf45b3ffe88e842c27145e7e646d63a89c371 +(Don't declare functions inline that aren't always defined as such) +--- + include/task.h | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/include/task.h b/include/task.h +index 00368fb..52827e9 100644 +--- a/include/task.h ++++ b/include/task.h +@@ -47,7 +47,7 @@ void interrupt_enable(void); + /** + * Return true if we are in interrupt context. + */ +-inline int in_interrupt_context(void); ++int in_interrupt_context(void); + + /** + * Set a task event. +-- +2.9.0 + diff --git a/projects/cros-ec/patches/nyan/0004-cortex-m-Use-assembly-exception-handler-and-routine-.patch b/projects/cros-ec/patches/nyan/0004-cortex-m-Use-assembly-exception-handler-and-routine-.patch new file mode 100644 index 00000000..88148eb4 --- /dev/null +++ b/projects/cros-ec/patches/nyan/0004-cortex-m-Use-assembly-exception-handler-and-routine-.patch @@ -0,0 +1,230 @@ +From f7d7b22a9e711783c99be55b2c1c437a6808f24d Mon Sep 17 00:00:00 2001 +From: Paul Kocialkowski <contact@paulk.fr> +Date: Sat, 23 Jul 2016 15:51:58 +0200 +Subject: [PATCH 4/4] cortex-m: Use assembly exception handler and routine for + task switching + +The way Cortex processors handle exceptions allows writing exception +routines directly in C, as return from exception is handled by providing +a special value for the link register. + +However, it is not safe to do this when doing context switching. In +particular, C handlers may push some general-purpose registers that +are used by the handler and pop them later, even when context switch +has happened in the meantime. While the processor will restore {r0-r3} +from the stack when returning from an exception, the C handler code +may push, use and pop another register, clobbering the value resulting +from the context switch. + +For this reason, it is safer to have assembly routines for exception +handlers that do context switching. + +BUG=chromium:631514 +BRANCH=None +TEST=Build and run big EC with a recent GCC version + +Change-Id: Ia356321021731e6e372af152c962d8f01c065da5 +Signed-off-by: Paul Kocialkowski <contact@paulk.fr> +--- + core/cortex-m/switch.S | 90 +++++++++++++++++++++++++++++++++++--------------- + core/cortex-m/task.c | 28 ++++------------ + 2 files changed, 69 insertions(+), 49 deletions(-) + +diff --git a/core/cortex-m/switch.S b/core/cortex-m/switch.S +index 92c7e51..80a99c8 100644 +--- a/core/cortex-m/switch.S ++++ b/core/cortex-m/switch.S +@@ -13,6 +13,48 @@ + .code 16 + + /** ++ * Start the task scheduling. r0 is a pointer to task_stack_ready, which is ++ * set to 1 after the task stack is set up. ++ */ ++.global __task_start ++.thumb_func ++__task_start: ++ ldr r2,=scratchpad @ area used as dummy thread stack for the first switch ++#ifdef CONFIG_FPU ++ mov r3, #6 @ use : priv. mode / thread stack / floating point on ++#else ++ mov r3, #2 @ use : priv. mode / thread stack / no floating point ++#endif ++ add r2, #17*4 @ put the pointer at the top of the stack ++ mov r1, #0 @ __Schedule parameter : re-schedule nothing ++ msr psp, r2 @ setup a thread stack up to the first context switch ++ mov r2, #1 ++ isb @ ensure the write is done ++ msr control, r3 ++ mov r3, r0 ++ mov r0, #0 @ __Schedule parameter : de-schedule nothing ++ isb @ ensure the write is done ++ str r2, [r3] @ Task scheduling is now active ++ bl __schedule @ execute the task with the highest priority ++ /* we should never return here */ ++ mov r0, #1 @ set to EC_ERROR_UNKNOWN ++ bx lr ++ ++/** ++ * SVC exception handler ++ */ ++.global svc_handler ++.thumb_func ++svc_handler: ++ push {lr} @ save link register ++ bl __svc_handler @ call svc handler helper ++ ldr r3,=current_task @ load the current task's address ++ ldr r1, [r3] @ load the current task ++ cmp r0, r1 @ compare with previous task returned by helper ++ beq svc_handler_return @ return if they are the same ++ /* continue to __switchto to switch to the new task */ ++ ++/** + * Task context switching + * + * Change the task scheduled after returning from the exception. +@@ -30,8 +72,6 @@ + * r0, r1, r2, r3, r12, lr, pc, psr, r4, r5, r6, r7, r8, r9, r10, r11 + * exception frame <|> additional registers + */ +-.global __switchto +-.thumb_func + __switchto: + mrs r3, psp @ get the task stack where the context has been saved + ldr r2, [r1] @ get the new scheduled task stack pointer +@@ -39,33 +79,29 @@ __switchto: + ldmia r2!, {r4-r11} @ restore r4-r11 for the next task context + str r3, [r0] @ save the task stack pointer in its context + msr psp, r2 @ set the process stack pointer to exception context +- bx lr @ return from exception ++ ++svc_handler_return: ++ pop {pc} @ return from exception or return to caller + + /** +- * Start the task scheduling. r0 is a pointer to task_stack_ready, which is +- * set to 1 after the task stack is set up. ++ * Resched task if needed: ++ * Continue iff a rescheduling event happened or profiling is active, ++ * and we are not called from another exception. + */ +-.global __task_start ++.global task_resched_if_needed + .thumb_func +-__task_start: +- ldr r2,=scratchpad @ area used as dummy thread stack for the first switch +-#ifdef CONFIG_FPU +- mov r3, #6 @ use : priv. mode / thread stack / floating point on +-#else +- mov r3, #2 @ use : priv. mode / thread stack / no floating point +-#endif +- add r2, #17*4 @ put the pointer at the top of the stack +- mov r1, #0 @ __Schedule parameter : re-schedule nothing +- msr psp, r2 @ setup a thread stack up to the first context switch +- mov r2, #1 +- isb @ ensure the write is done +- msr control, r3 +- mov r3, r0 +- mov r0, #0 @ __Schedule parameter : de-schedule nothing +- isb @ ensure the write is done +- str r2, [r3] @ Task scheduling is now active +- bl __schedule @ execute the task with the highest priority +- /* we should never return here */ +- mov r0, #1 @ set to EC_ERROR_UNKNOWN +- bx lr ++task_resched_if_needed: ++ push {lr} @ save link register ++ ldr r3,=need_resched_or_profiling @ load need's address ++ ldr r1, [r3] @ load need ++ cbz r1, task_resched_if_needed_return @ return if there is no need ++ and r0, #0xf @ called from another exception ++ cmp r0, #1 @ check bit ++ beq task_resched_if_needed_return @ return if called from exception ++ movs r1, #0 @ desched nothing ++ movs r0, #0 @ resched nothing ++ bl svc_handler @ re-schedule the highest priority ++ @ task + ++task_resched_if_needed_return: ++ pop {pc} @ return to caller +diff --git a/core/cortex-m/task.c b/core/cortex-m/task.c +index bfb3a9b..9935a28 100644 +--- a/core/cortex-m/task.c ++++ b/core/cortex-m/task.c +@@ -57,7 +57,6 @@ static uint32_t task_switches; /* Number of times active task changed */ + static uint32_t irq_dist[CONFIG_IRQ_COUNT]; /* Distribution of IRQ calls */ + #endif + +-extern void __switchto(task_ *from, task_ *to); + extern int __task_start(int *task_stack_ready); + + #ifndef CONFIG_LOW_POWER_IDLE +@@ -124,7 +123,7 @@ uint32_t scratchpad[17+18]; + uint32_t scratchpad[17]; + #endif + +-static task_ *current_task = (task_ *)scratchpad; ++task_ *current_task = (task_ *)scratchpad; + + /* + * Should IRQs chain to svc_handler()? This should be set if either of the +@@ -137,7 +136,7 @@ static task_ *current_task = (task_ *)scratchpad; + * task unblocking. After checking for a task switch, svc_handler() will clear + * the flag (unless profiling is also enabled; then the flag remains set). + */ +-static int need_resched_or_profiling; ++int need_resched_or_profiling; + + /* + * Bitmap of all tasks ready to be run. +@@ -197,7 +196,7 @@ int task_start_called(void) + /** + * Scheduling system call + */ +-void svc_handler(int desched, task_id_t resched) ++task_ *__svc_handler(int desched, task_id_t resched) + { + task_ *current, *next; + #ifdef CONFIG_TASK_PROFILING +@@ -264,16 +263,13 @@ void svc_handler(int desched, task_id_t resched) + need_resched_or_profiling = 0; + #endif + +- /* Nothing to do */ +- if (next == current) +- return; +- + /* Switch to new task */ + #ifdef CONFIG_TASK_PROFILING +- task_switches++; ++ if (next != current) ++ task_switches++; + #endif + current_task = next; +- __switchto(current, next); ++ return current; + } + + void __schedule(int desched, int resched) +@@ -313,18 +309,6 @@ void task_start_irq_handler(void *excep_return) + } + #endif + +-void task_resched_if_needed(void *excep_return) +-{ +- /* +- * Continue iff a rescheduling event happened or profiling is active, +- * and we are not called from another exception. +- */ +- if (!need_resched_or_profiling || (((uint32_t)excep_return & 0xf) == 1)) +- return; +- +- svc_handler(0, 0); +-} +- + static uint32_t __wait_evt(int timeout_us, task_id_t resched) + { + task_ *tsk = current_task; +-- +2.9.0 + diff --git a/projects/cros-ec/patches/veyron/0001-ec-fix-a-clang-warning-by-use-a-unused-variable.patch b/projects/cros-ec/patches/veyron/0001-ec-fix-a-clang-warning-by-use-a-unused-variable.patch new file mode 100644 index 00000000..82d6de83 --- /dev/null +++ b/projects/cros-ec/patches/veyron/0001-ec-fix-a-clang-warning-by-use-a-unused-variable.patch @@ -0,0 +1,38 @@ +From 35987639080ef4293bffbc1ce21de4d8a35b41db Mon Sep 17 00:00:00 2001 +From: Yunlian Jiang <yunlian@google.com> +Date: Mon, 20 Apr 2015 09:38:56 -0700 +Subject: [PATCH 1/6] ec: fix a clang warning by use a unused variable. + +This uses the variable 'usage' in an error message to fix a clang +warning. + +BUG=chromium:475960 +TEST=CC=x86_64-cros-linux-gnu-clang emerge-falco ec-devutils +BRANCH=none +Signed-off-by: yunlian@chromium.org + +Change-Id: Ic5703636040805661c7b81b83fc182e127ceab8c +Reviewed-on: https://chromium-review.googlesource.com/266404 +Reviewed-by: Vincent Palatin <vpalatin@chromium.org> +Tested-by: Yunlian Jiang <yunlian@chromium.org> +Commit-Queue: Yunlian Jiang <yunlian@chromium.org> +--- + util/lbcc.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/util/lbcc.c b/util/lbcc.c +index b34b21e..953f422 100644 +--- a/util/lbcc.c ++++ b/util/lbcc.c +@@ -630,7 +630,7 @@ int main(int argc, char *argv[]) + } + + if (errorcnt) { +- fprintf(stderr, "\nUsage: %s [options] ...\n\n", progname); ++ fprintf(stderr, usage, progname); + exit(1); + } + +-- +2.9.0 + diff --git a/projects/cros-ec/patches/veyron/0002-use-_DEFAULT_SOURCE-for-newer-glibc.patch b/projects/cros-ec/patches/veyron/0002-use-_DEFAULT_SOURCE-for-newer-glibc.patch new file mode 100644 index 00000000..7da2c967 --- /dev/null +++ b/projects/cros-ec/patches/veyron/0002-use-_DEFAULT_SOURCE-for-newer-glibc.patch @@ -0,0 +1,53 @@ +From d2f946caf27adf4518cb657da39e296366d0b53f Mon Sep 17 00:00:00 2001 +From: Mike Frysinger <vapier@chromium.org> +Date: Mon, 7 Dec 2015 21:46:13 -0500 +Subject: [PATCH 2/6] use _DEFAULT_SOURCE for newer glibc + +Newer versions of glibc have moved to _DEFAULT_SOURCE and away from +_BSD_SOURCE. Trying to use the BSD define by itself leads to warnings +which causes build failures. + +BRANCH=none +BUG=None +TEST=precq still works + +Signed-off-by: Mike Frysinger <vapier@chromium.org> +Change-Id: Ice24b84dc6a540695fc7b76e8f22a4c85c301976 +Reviewed-on: https://chromium-review.googlesource.com/316730 +Reviewed-by: Bill Richardson <wfrichar@chromium.org> +--- + util/ec_uartd.c | 3 ++- + util/stm32mon.c | 3 ++- + 2 files changed, 4 insertions(+), 2 deletions(-) + +diff --git a/util/ec_uartd.c b/util/ec_uartd.c +index 82823c4..678932e 100644 +--- a/util/ec_uartd.c ++++ b/util/ec_uartd.c +@@ -11,7 +11,8 @@ + */ + + /* Force header files to define grantpt(), posix_openpt(), cfmakeraw() */ +-#define _BSD_SOURCE ++#define _DEFAULT_SOURCE /* Newer glibc */ ++#define _BSD_SOURCE /* Older glibc */ + #define _XOPEN_SOURCE 600 + /* Force header file to declare ptsname_r(), etc. */ + #ifndef _GNU_SOURCE +diff --git a/util/stm32mon.c b/util/stm32mon.c +index 2de9400..ed1a7ee 100644 +--- a/util/stm32mon.c ++++ b/util/stm32mon.c +@@ -13,7 +13,8 @@ + */ + + /* use cfmakeraw() */ +-#define _BSD_SOURCE ++#define _DEFAULT_SOURCE /* Newer glibc */ ++#define _BSD_SOURCE /* Older glibc */ + + #include <arpa/inet.h> + #include <errno.h> +-- +2.9.0 + diff --git a/projects/cros-ec/patches/veyron/0003-Enforce-compilation-without-system-headers.patch b/projects/cros-ec/patches/veyron/0003-Enforce-compilation-without-system-headers.patch new file mode 100644 index 00000000..a97aa901 --- /dev/null +++ b/projects/cros-ec/patches/veyron/0003-Enforce-compilation-without-system-headers.patch @@ -0,0 +1,44 @@ +From 63bb6f6effbaae9864366588464a7b9354c9a623 Mon Sep 17 00:00:00 2001 +From: Paul Kocialkowski <contact@paulk.fr> +Date: Wed, 20 Jul 2016 16:26:32 +0200 +Subject: [PATCH 3/6] Enforce compilation without system headers + +This is based on commit bc404c94b4ab1e6a62e607fd7ef034aa31d6388e +(Enforce compilation without system headers) +--- + Makefile | 5 +++-- + Makefile.toolchain | 2 +- + 2 files changed, 4 insertions(+), 3 deletions(-) + +diff --git a/Makefile b/Makefile +index 01581fb..195ea44 100644 +--- a/Makefile ++++ b/Makefile +@@ -99,8 +99,9 @@ _rw_size_str:=$(shell echo "CONFIG_FW_RW_SIZE" | $(CPP) $(CPPFLAGS) -P \ + _rw_size:=$(shell echo "$$(($(_rw_size_str)))") + + # Get RSA key size from board defines +-_rsa_size:=$(shell echo "CONFIG_RSA_KEY_SIZE" | $(CPP) $(CPPFLAGS) -P \ +- -Ichip/$(CHIP) -Iboard/$(BOARD) -imacros include/rsa.h) ++_rsa_size:=$(shell echo "CONFIG_RSA_KEY_SIZE" | $(CPP) $(CPPFLAGS) \ ++ $(CFLAGS_WARN) -P -Ichip/$(CHIP) -Iboard/$(BOARD) \ ++ -imacros include/rsa.h) + $(eval RSA_KEY_SIZE=$(_rsa_size)) + + $(eval BOARD_$(UC_BOARD)=y) +diff --git a/Makefile.toolchain b/Makefile.toolchain +index 43f390c..898129c 100644 +--- a/Makefile.toolchain ++++ b/Makefile.toolchain +@@ -19,7 +19,7 @@ BUILDCC?=gcc + HOSTCC?=$(HOST_CROSS_COMPILE)gcc + + CFLAGS_WARN=-Wall -Werror -Wundef -Wstrict-prototypes -Wno-trigraphs \ +- -fno-strict-aliasing -fno-common \ ++ -fno-strict-aliasing -fno-common -ffreestanding -fno-builtin \ + -Werror-implicit-function-declaration -Wno-format-security \ + -fno-delete-null-pointer-checks -Wdeclaration-after-statement \ + -Wno-pointer-sign -fno-strict-overflow -fconserve-stack +-- +2.9.0 + diff --git a/projects/cros-ec/patches/veyron/0004-Don-t-declare-functions-inline-that-aren-t-always-de.patch b/projects/cros-ec/patches/veyron/0004-Don-t-declare-functions-inline-that-aren-t-always-de.patch new file mode 100644 index 00000000..f089dbe9 --- /dev/null +++ b/projects/cros-ec/patches/veyron/0004-Don-t-declare-functions-inline-that-aren-t-always-de.patch @@ -0,0 +1,28 @@ +From 3515f1d744cbcdb37471e898277aa6b1ddd3d0ee Mon Sep 17 00:00:00 2001 +From: Paul Kocialkowski <contact@paulk.fr> +Date: Wed, 20 Jul 2016 16:27:05 +0200 +Subject: [PATCH 4/6] Don't declare functions inline that aren't always defined + as such + +This is based on commit 960cf45b3ffe88e842c27145e7e646d63a89c371 +(Don't declare functions inline that aren't always defined as such) +--- + include/task.h | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/include/task.h b/include/task.h +index cb96281..85d5b00 100644 +--- a/include/task.h ++++ b/include/task.h +@@ -47,7 +47,7 @@ void interrupt_enable(void); + /** + * Return true if we are in interrupt context. + */ +-inline int in_interrupt_context(void); ++int in_interrupt_context(void); + + /** + * Set a task event. +-- +2.9.0 + diff --git a/projects/cros-ec/patches/veyron/0005-Don-t-include-missing-and-unnecessary-math-header.patch b/projects/cros-ec/patches/veyron/0005-Don-t-include-missing-and-unnecessary-math-header.patch new file mode 100644 index 00000000..0a099213 --- /dev/null +++ b/projects/cros-ec/patches/veyron/0005-Don-t-include-missing-and-unnecessary-math-header.patch @@ -0,0 +1,29 @@ +From 913b2f1265bd7f3ebe6cf4cba92c20c5a423a6c3 Mon Sep 17 00:00:00 2001 +From: Paul Kocialkowski <contact@paulk.fr> +Date: Tue, 2 Aug 2016 12:05:55 +0200 +Subject: [PATCH 5/6] Don't include missing and unnecessary math header + +This removes the inclusion of an unnecessary math header that is neither +found nor necessary for non-cortex-m ECs. + +Change-Id: I56a04178dadedb76f841504fa645e2d43900d25f +Signed-off-by: Paul Kocialkowski <contact@paulk.fr> +--- + common/math_util.c | 1 - + 1 file changed, 1 deletion(-) + +diff --git a/common/math_util.c b/common/math_util.c +index 120d13d..34a267d 100644 +--- a/common/math_util.c ++++ b/common/math_util.c +@@ -6,7 +6,6 @@ + /* Common math functions. */ + + #include "common.h" +-#include "math.h" + #include "math_util.h" + #include "util.h" + +-- +2.9.0 + diff --git a/projects/cros-ec/patches/veyron/0006-cortex-m0-Use-assembly-exception-handlers-for-task-s.patch b/projects/cros-ec/patches/veyron/0006-cortex-m0-Use-assembly-exception-handlers-for-task-s.patch new file mode 100644 index 00000000..f0175825 --- /dev/null +++ b/projects/cros-ec/patches/veyron/0006-cortex-m0-Use-assembly-exception-handlers-for-task-s.patch @@ -0,0 +1,219 @@ +From 9dd7ae82d3f3fa9dae31a442365e233a0b44cce3 Mon Sep 17 00:00:00 2001 +From: Paul Kocialkowski <contact@paulk.fr> +Date: Sat, 23 Jul 2016 14:17:32 +0200 +Subject: [PATCH 6/6] cortex-m0: Use assembly exception handlers for task + switching + +The way Cortex processors handle exceptions allows writing exception +routines directly in C, as return from exception is handled by providing +a special value for the link register. + +However, it is not safe to do this when doing context switching. In +particular, C handlers may push some general-purpose registers that +are used by the handler and pop them later, even when context switch +has happened in the meantime. While the processor will restore {r0-r3} +from the stack when returning from an exception, the C handler code +may push, use and pop another register, such as r4. + +It turns out that GCC 4.8 would generally only use r3 in svc_handler and +pendsv_handler, but newer versions tend to use r4, thus clobbering r4 +that was restored from the context switch and leading up to a fault +when r4 is used by the task code. + +An occurrence of this behaviour takes place with GCC > 4.8 in __wait_evt, +where "me" is stored in r4, which gets clobbered after an exception +triggers pendsv_handler. The exception handler uses r4 internally, does +a context switch and then restores the previous value of r4, which is +not restored by the processor's internal, thus clobbering r4. +This ends up with the following assertion failure: +'tskid < TASK_ID_COUNT' in timer_cancel() at common/timer.c:137 + +For this reason, it is safer to have assembly routines for exception +handlers that do context switching. + +BUG=chromium:631514 +BRANCH=None +TEST=Build and run speedy EC with a recent GCC version + +Change-Id: Ib068bc12ce2204aee3e0f563efcb94f15aa87013 +Signed-off-by: Paul Kocialkowski <contact@paulk.fr> +--- + core/cortex-m0/switch.S | 81 ++++++++++++++++++++++++++++++++++--------------- + core/cortex-m0/task.c | 27 +---------------- + 2 files changed, 58 insertions(+), 50 deletions(-) + +diff --git a/core/cortex-m0/switch.S b/core/cortex-m0/switch.S +index 95ea29e..d4b47cd 100644 +--- a/core/cortex-m0/switch.S ++++ b/core/cortex-m0/switch.S +@@ -7,12 +7,52 @@ + + #include "config.h" + ++#define CPU_SCB_ICSR 0xe000ed04 ++ + .text + + .syntax unified + .code 16 + + /** ++ * Start the task scheduling. r0 is a pointer to task_stack_ready, which is ++ * set to 1 after the task stack is set up. ++ */ ++.global __task_start ++.thumb_func ++__task_start: ++ ldr r2,=scratchpad @ area used as dummy thread stack for the first switch ++ movs r3, #2 @ use : priv. mode / thread stack / no floating point ++ adds r2, #17*4 @ put the pointer at the top of the stack ++ movs r1, #0 @ __Schedule parameter : re-schedule nothing ++ msr psp, r2 @ setup a thread stack up to the first context switch ++ movs r2, #1 ++ isb @ ensure the write is done ++ msr control, r3 ++ movs r3, r0 ++ movs r0, #0 @ __Schedule parameter : de-schedule nothing ++ isb @ ensure the write is done ++ str r2, [r3] @ Task scheduling is now active ++ bl __schedule @ execute the task with the highest priority ++ /* we should never return here */ ++ movs r0, #1 @ set to EC_ERROR_UNKNOWN ++ bx lr ++ ++/** ++ * SVC exception handler ++ */ ++.global svc_handler ++.thumb_func ++svc_handler: ++ push {lr} @ save link register ++ bl __svc_handler @ call svc handler helper ++ ldr r3,=current_task @ load the current task's address ++ ldr r1, [r3] @ load the current task ++ cmp r0, r1 @ compare with previous task returned by helper ++ beq svc_handler_return @ return if they are the same ++ /* continue to __switchto to switch to the new task */ ++ ++/** + * Task context switching + * + * Change the task scheduled after returning from the exception. +@@ -30,8 +70,6 @@ + * r8, r9, r10, r11, r4, r5, r6, r7, r0, r1, r2, r3, r12, lr, pc, psr + * additional registers <|> exception frame + */ +-.global __switchto +-.thumb_func + __switchto: + mrs r2, psp @ get the task stack where the context has been saved + mov r3, sp +@@ -53,29 +91,24 @@ __switchto: + mov r11, r7 + ldmia r2!, {r4-r7} @ restore r4-r7 for the next task context + msr psp, r2 @ set the process stack pointer to exception context +- bx lr @ return from exception ++ ++svc_handler_return: ++ pop {pc} @ return from exception or return to caller + + /** +- * Start the task scheduling. r0 is a pointer to task_stack_ready, which is +- * set to 1 after the task stack is set up. ++ * PendSVC exception handler + */ +-.global __task_start ++.global pendsv_handler + .thumb_func +-__task_start: +- ldr r2,=scratchpad @ area used as dummy thread stack for the first switch +- movs r3, #2 @ use : priv. mode / thread stack / no floating point +- adds r2, #17*4 @ put the pointer at the top of the stack +- movs r1, #0 @ __Schedule parameter : re-schedule nothing +- msr psp, r2 @ setup a thread stack up to the first context switch +- movs r2, #1 +- isb @ ensure the write is done +- msr control, r3 +- movs r3, r0 +- movs r0, #0 @ __Schedule parameter : de-schedule nothing +- isb @ ensure the write is done +- str r2, [r3] @ Task scheduling is now active +- bl __schedule @ execute the task with the highest priority +- /* we should never return here */ +- movs r0, #1 @ set to EC_ERROR_UNKNOWN +- bx lr +- ++pendsv_handler: ++ push {lr} @ save link register ++ ldr r0, =#CPU_SCB_ICSR @ load CPU_SCB_ICSR's address ++ movs r1, #1 @ prepare left shift (1 << 27) ++ lsls r1, #27 @ shift the bit ++ str r1, [r0] @ clear pending flag ++ cpsid i @ ensure we have priority 0 during re-scheduling ++ movs r1, #0 @ desched nothing ++ movs r0, #0 @ resched nothing ++ bl svc_handler @ re-schedule the highest priority task ++ cpsie i @ leave priority 0 ++ pop {pc} @ return from exception +diff --git a/core/cortex-m0/task.c b/core/cortex-m0/task.c +index e51621b..f96ccf8 100644 +--- a/core/cortex-m0/task.c ++++ b/core/cortex-m0/task.c +@@ -57,7 +57,6 @@ static uint32_t task_switches; /* Number of times active task changed */ + static uint32_t irq_dist[CONFIG_IRQ_COUNT]; /* Distribution of IRQ calls */ + #endif + +-extern void __switchto(task_ *from, task_ *to); + extern int __task_start(int *task_stack_ready); + + #ifndef CONFIG_LOW_POWER_IDLE +@@ -120,7 +119,7 @@ uint8_t task_stacks[0 + /* Reserve space to discard context on first context switch. */ + uint32_t scratchpad[17]; + +-static task_ *current_task = (task_ *)scratchpad; ++task_ *current_task = (task_ *)scratchpad; + + /* + * Bitmap of all tasks ready to be run. +@@ -242,18 +241,6 @@ task_ *__svc_handler(int desched, task_id_t resched) + return current; + } + +-void svc_handler(int desched, task_id_t resched) +-{ +- /* +- * The layout of the this routine (and the __svc_handler companion one) +- * ensures that we are getting the right tail call optimization from +- * the compiler. +- */ +- task_ *prev = __svc_handler(desched, resched); +- if (current_task != prev) +- __switchto(prev, current_task); +-} +- + void __schedule(int desched, int resched) + { + register int p0 asm("r0") = desched; +@@ -262,18 +249,6 @@ void __schedule(int desched, int resched) + asm("svc 0" : : "r"(p0), "r"(p1)); + } + +-void pendsv_handler(void) +-{ +- /* Clear pending flag */ +- CPU_SCB_ICSR = (1 << 27); +- +- /* ensure we have priority 0 during re-scheduling */ +- __asm__ __volatile__("cpsid i"); +- /* re-schedule the highest priority task */ +- svc_handler(0, 0); +- __asm__ __volatile__("cpsie i"); +-} +- + #ifdef CONFIG_TASK_PROFILING + void task_start_irq_handler(void *excep_return) + { +-- +2.9.0 + |