Paper build system initial import into Libreboot

This is the initial import of the Paper build system into Libreboot.
It was written as a flexible and painless replacement for the Libreboot
build system, allowing to support many different configurations.
It currently only supports the following CrOS devices:
* Chromebook 13 CB5-311 (nyan big)
* Chromebook 14 (nyan blaze)
* Chromebook 11 (HiSense) (veyron jerry)
* Chromebit CS10 (veyron mickey)
* Chromebook Flip C100PA (veyron minnie)
* Chromebook C201PA (veyron speedy)

The build system also supports building various tools and provides
various scripts to ease the installation on CrOS devices.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>

6 files changed, 411 insertions, 0 deletions

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
+