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-rw-r--r--src/arch/x86/Kconfig5
-rw-r--r--src/arch/x86/Makefile.inc25
-rw-r--r--src/arch/x86/exit_car.S106
-rw-r--r--src/arch/x86/include/arch/cpu.h37
-rw-r--r--src/arch/x86/memlayout.ld2
-rw-r--r--src/arch/x86/postcar_loader.c115
-rw-r--r--src/commonlib/Makefile.inc4
-rw-r--r--src/commonlib/include/commonlib/cbmem_id.h2
-rw-r--r--src/console/Makefile.inc5
-rw-r--r--src/cpu/x86/lapic/Makefile.inc1
-rw-r--r--src/include/console/console.h2
-rw-r--r--src/include/memlayout.h12
-rw-r--r--src/include/rules.h25
-rw-r--r--src/lib/Makefile.inc27
-rw-r--r--src/lib/program.ld9
15 files changed, 370 insertions, 7 deletions
diff --git a/src/arch/x86/Kconfig b/src/arch/x86/Kconfig
index 4102b6805f..724c4dba61 100644
--- a/src/arch/x86/Kconfig
+++ b/src/arch/x86/Kconfig
@@ -167,3 +167,8 @@ config ROMSTAGE_ADDR
config VERSTAGE_ADDR
hex
default 0x2000000
+
+# Use the post CAR infrastructure for tearing down cache-as-ram
+# from a program loaded in ram and subsequently loading ramstage.
+config POSTCAR_STAGE
+ def_bool n
diff --git a/src/arch/x86/Makefile.inc b/src/arch/x86/Makefile.inc
index 1ba879573e..10664c3ba3 100644
--- a/src/arch/x86/Makefile.inc
+++ b/src/arch/x86/Makefile.inc
@@ -331,6 +331,7 @@ endif # CONFIG_ARCH_RAMSTAGE_X86_32 / CONFIG_ARCH_RAMSTAGE_X86_64
ifeq ($(CONFIG_ARCH_ROMSTAGE_X86_32)$(CONFIG_ARCH_ROMSTAGE_X86_64),y)
+romstage-$(CONFIG_POSTCAR_STAGE) += postcar_loader.c
romstage-y += cbmem.c
romstage-y += boot.c
@@ -390,3 +391,27 @@ rmodules_x86_64-y += memmove.c
endif
endif # CONFIG_ARCH_RAMSTAGE_X86_32 / CONFIG_ARCH_RAMSTAGE_X86_64
+
+$(eval $(call create_class_compiler,postcar,x86_32))
+postcar-generic-ccopts += -D__POSTCAR__
+
+postcar-y += boot.c
+postcar-y += cbfs_and_run.c
+postcar-y += exit_car.S
+postcar-y += memset.c
+postcar-y += memcpy.c
+postcar-y += memmove.c
+postcar-y += memlayout.ld
+postcar-$(CONFIG_X86_TOP4G_BOOTMEDIA_MAP) += mmap_boot.c
+
+$(objcbfs)/postcar.debug: $$(postcar-objs)
+ @printf " LINK $(subst $(obj)/,,$(@))\n"
+ $(LD_postcar) $(LDFLAGS_postcar) -o $@ -L$(obj) $(COMPILER_RT_FLAGS_postcar) --whole-archive --start-group $(filter-out %.ld,$^) --no-whole-archive $(COMPILER_RT_postcar) --end-group -T $(call src-to-obj,postcar,src/arch/x86/memlayout.ld)
+
+$(objcbfs)/postcar.elf: $(objcbfs)/postcar.debug.rmod
+ cp $< $@
+
+cbfs-files-$(CONFIG_POSTCAR_STAGE) += $(CONFIG_CBFS_PREFIX)/postcar
+$(CONFIG_CBFS_PREFIX)/postcar-file := $(objcbfs)/postcar.elf
+$(CONFIG_CBFS_PREFIX)/postcar-type := stage
+$(CONFIG_CBFS_PREFIX)/postcar-compression := none
diff --git a/src/arch/x86/exit_car.S b/src/arch/x86/exit_car.S
new file mode 100644
index 0000000000..e04bd04b25
--- /dev/null
+++ b/src/arch/x86/exit_car.S
@@ -0,0 +1,106 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <cpu/x86/mtrr.h>
+#include <cpu/x86/cr.h>
+
+.section ".module_parameters", "aw", @progbits
+/* stack_top indicates the stack to pull MTRR information from. */
+stack_top:
+.long 0
+.long 0
+
+.text
+.global _start
+_start:
+ /* chipset_teardown_car() is expected to disable cache-as-ram. */
+ call chipset_teardown_car
+
+ /* Enable caching if not already enabled. */
+ mov %cr0, %eax
+ and $(~(CR0_CD | CR0_NW)), %eax
+ mov %eax, %cr0
+
+ /* Ensure cache is clean. */
+ invd
+
+ /* Set up new stack. */
+ mov stack_top, %esp
+
+ /*
+ * Honor variable MTRR information pushed on the stack with the
+ * following layout:
+ *
+ * Offset: Value
+ * ...
+ * 0x14: MTRR mask 0 63:32
+ * 0x10: MTRR mask 0 31:0
+ * 0x0c: MTRR base 0 63:32
+ * 0x08: MTRR base 0 31:0
+ * 0x04: Number of variable MTRRs to set
+ * 0x00: Number of variable MTRRs to clear
+ */
+
+ /* Clear variable MTRRs. */
+ pop %ebx /* Number to clear */
+ test %ebx, %ebx
+ jz 2f
+ xor %eax, %eax
+ xor %edx, %edx
+ mov $(MTRR_PHYS_BASE(0)), %ecx
+1:
+ wrmsr
+ inc %ecx
+ wrmsr
+ inc %ecx
+ dec %ebx
+ jnz 1b
+2:
+
+ /* Set Variable MTRRs based on stack contents. */
+ pop %ebx /* Number to set. */
+ test %ebx, %ebx
+ jz 2f
+ mov $(MTRR_PHYS_BASE(0)), %ecx
+1:
+ /* Write MTRR base. */
+ pop %eax
+ pop %edx
+ wrmsr
+ inc %ecx
+ /* Write MTRR mask. */
+ pop %eax
+ pop %edx
+ wrmsr
+ inc %ecx
+
+ dec %ebx
+ jnz 1b
+2:
+
+ /* Enable MTRR. */
+ mov $(MTRR_DEF_TYPE_MSR), %ecx
+ rdmsr
+ /* Make default type uncacheable. */
+ and $(~(MTRR_DEF_TYPE_MASK)), %eax
+ or $(MTRR_DEF_TYPE_EN), %eax
+ wrmsr
+
+ /* Load and run ramstage. */
+ call copy_and_run
+ /* Should never return. */
+1:
+ jmp 1b
diff --git a/src/arch/x86/include/arch/cpu.h b/src/arch/x86/include/arch/cpu.h
index f50901fe73..5c26bcf74d 100644
--- a/src/arch/x86/include/arch/cpu.h
+++ b/src/arch/x86/include/arch/cpu.h
@@ -15,6 +15,7 @@
#define ARCH_CPU_H
#include <stdint.h>
+#include <stddef.h>
#include <rules.h>
/*
@@ -246,6 +247,42 @@ static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
* cache-as-ram.
*/
void asmlinkage car_stage_entry(void);
+
+/*
+ * Support setting up a stack frame consisting of MTRR information
+ * for use in bootstrapping the caching attributes after cache-as-ram
+ * is torn down.
+ */
+
+struct postcar_frame {
+ uintptr_t stack;
+ uint32_t upper_mask;
+ int max_var_mttrs;
+ int num_var_mttrs;
+};
+
+/*
+ * Initialize postcar_frame object allocating stack size in cbmem
+ * with the provided size. Returns 0 on success, < 0 on error.
+ */
+int postcar_frame_init(struct postcar_frame *pcf, size_t stack_size);
+
+/*
+ * Add variable MTRR covering the provided range with MTRR type.
+ */
+void postcar_frame_add_mtrr(struct postcar_frame *pcf,
+ uintptr_t addr, size_t size, int type);
+
+/*
+ * Load and run a program that takes control of execution that
+ * tears down CAR and loads ramstage. The postcar_frame object
+ * indicates how to set up the frame. If caching is enabled at
+ * the time of the call it is up to the platform code to handle
+ * coherency with dirty lines in the cache using some mechansim
+ * such as platform_prog_run() because run_postcar_phase()
+ * utilizes prog_run() internally.
+ */
+void run_postcar_phase(struct postcar_frame *pcf);
#endif
#endif /* ARCH_CPU_H */
diff --git a/src/arch/x86/memlayout.ld b/src/arch/x86/memlayout.ld
index 5661104179..e6db0b8fe6 100644
--- a/src/arch/x86/memlayout.ld
+++ b/src/arch/x86/memlayout.ld
@@ -51,6 +51,8 @@ SECTIONS
/* Pull in the cache-as-ram rules. */
#include "car.ld"
+#elif ENV_POSTCAR
+ POSTCAR(32M, 1M)
#endif
}
diff --git a/src/arch/x86/postcar_loader.c b/src/arch/x86/postcar_loader.c
new file mode 100644
index 0000000000..580cc4585c
--- /dev/null
+++ b/src/arch/x86/postcar_loader.c
@@ -0,0 +1,115 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/cpu.h>
+#include <cbmem.h>
+#include <console/console.h>
+#include <cpu/x86/msr.h>
+#include <cpu/x86/mtrr.h>
+#include <program_loading.h>
+#include <rmodule.h>
+
+static inline void stack_push(struct postcar_frame *pcf, uint32_t val)
+{
+ uint32_t *ptr;
+
+ pcf->stack -= sizeof(val);
+ ptr = (void *)pcf->stack;
+ *ptr = val;
+}
+
+int postcar_frame_init(struct postcar_frame *pcf, size_t stack_size)
+{
+ void *stack;
+ msr_t msr;
+
+ msr = rdmsr(MTRR_CAP_MSR);
+
+ stack = cbmem_add(CBMEM_ID_ROMSTAGE_RAM_STACK, stack_size);
+ if (stack == NULL) {
+ printk(BIOS_ERR, "Couldn't add %zd byte stack in cbmem.\n",
+ stack_size);
+ return -1;
+ }
+
+ pcf->stack = (uintptr_t)stack;
+ pcf->stack += stack_size;
+
+ pcf->upper_mask = (1 << (cpu_phys_address_size() - 32)) - 1;
+
+ pcf->max_var_mttrs = msr.lo & MTRR_CAP_VCNT;
+
+ pcf->num_var_mttrs = 0;
+
+ return 0;
+}
+
+void postcar_frame_add_mtrr(struct postcar_frame *pcf,
+ uintptr_t addr, size_t size, int type)
+{
+ size_t align;
+
+ if (pcf->num_var_mttrs >= pcf->max_var_mttrs) {
+ printk(BIOS_ERR, "No more variable MTRRs: %d\n",
+ pcf->max_var_mttrs);
+ return;
+ }
+
+ /* Determine address alignment by lowest bit set in address. */
+ align = addr & (addr ^ (addr - 1));
+
+ if (align < size) {
+ printk(BIOS_ERR, "Address (%lx) alignment (%zx) < size (%zx)\n",
+ addr, align, size);
+ size = align;
+ }
+
+ /* Push MTRR mask then base -- upper 32-bits then lower 32-bits. */
+ stack_push(pcf, pcf->upper_mask);
+ stack_push(pcf, ~(size - 1) | MTRR_PHYS_MASK_VALID);
+ stack_push(pcf, 0);
+ stack_push(pcf, addr | type);
+ pcf->num_var_mttrs++;
+}
+
+void run_postcar_phase(struct postcar_frame *pcf)
+{
+ struct prog prog =
+ PROG_INIT(PROG_UNKNOWN, CONFIG_CBFS_PREFIX "/postcar");
+ struct rmod_stage_load rsl = {
+ .cbmem_id = CBMEM_ID_AFTER_CAR,
+ .prog = &prog,
+ };
+
+ /*
+ * Place the number of used variable MTRRs on stack then max number
+ * of variable MTRRs supported in the system.
+ */
+ stack_push(pcf, pcf->num_var_mttrs);
+ stack_push(pcf, pcf->max_var_mttrs);
+
+ if (prog_locate(&prog))
+ die("Failed to locate after CAR program.\n");
+ if (rmodule_stage_load(&rsl))
+ die("Failed to load after CAR program.\n");
+
+ /* Set the stack pointer within parameters of the program loaded. */
+ if (rsl.params == NULL)
+ die("No parameters found in after CAR program.\n");
+
+ *(uintptr_t *)rsl.params = pcf->stack;
+
+ prog_run(&prog);
+}
diff --git a/src/commonlib/Makefile.inc b/src/commonlib/Makefile.inc
index 2752922067..7c14f7cb8c 100644
--- a/src/commonlib/Makefile.inc
+++ b/src/commonlib/Makefile.inc
@@ -2,12 +2,14 @@ bootblock-y += mem_pool.c
verstage-y += mem_pool.c
romstage-y += mem_pool.c
ramstage-y += mem_pool.c
+postcar-y += mem_pool.c
bootblock-y += region.c
verstage-y += region.c
romstage-y += region.c
ramstage-y += region.c
smm-y += region.c
+postcar-y += region.c
ramstage-$(CONFIG_PLATFORM_USES_FSP1_1) += fsp1_1_relocate.c
@@ -16,8 +18,10 @@ verstage-y += cbfs.c
romstage-y += cbfs.c
ramstage-y += cbfs.c
smm-y += cbfs.c
+postcar-y += cbfs.c
bootblock-y += lz4_wrapper.c
verstage-y += lz4_wrapper.c
romstage-y += lz4_wrapper.c
ramstage-y += lz4_wrapper.c
+postcar-y += lz4_wrapper.c
diff --git a/src/commonlib/include/commonlib/cbmem_id.h b/src/commonlib/include/commonlib/cbmem_id.h
index 46c5d49e6b..adeb291728 100644
--- a/src/commonlib/include/commonlib/cbmem_id.h
+++ b/src/commonlib/include/commonlib/cbmem_id.h
@@ -20,6 +20,7 @@
#define CBMEM_ID_ACPI 0x41435049
#define CBMEM_ID_ACPI_GNVS 0x474e5653
#define CBMEM_ID_ACPI_GNVS_PTR 0x474e5650
+#define CBMEM_ID_AFTER_CAR 0xc4787a93
#define CBMEM_ID_AGESA_RUNTIME 0x41474553
#define CBMEM_ID_AMDMCT_MEMINFO 0x494D454E
#define CBMEM_ID_CAR_GLOBALS 0xcac4e6a3
@@ -71,6 +72,7 @@
{ CBMEM_ID_ACPI_GNVS, "ACPI GNVS " }, \
{ CBMEM_ID_ACPI_GNVS_PTR, "GNVS PTR " }, \
{ CBMEM_ID_AGESA_RUNTIME, "AGESA RSVD " }, \
+ { CBMEM_ID_AFTER_CAR, "AFTER CAR" }, \
{ CBMEM_ID_AMDMCT_MEMINFO, "AMDMEM INFO" }, \
{ CBMEM_ID_CAR_GLOBALS, "CAR GLOBALS" }, \
{ CBMEM_ID_CBTABLE, "COREBOOT " }, \
diff --git a/src/console/Makefile.inc b/src/console/Makefile.inc
index 94b456c664..0fee12aa48 100644
--- a/src/console/Makefile.inc
+++ b/src/console/Makefile.inc
@@ -18,6 +18,11 @@ romstage-y += init.c console.c
romstage-y += post.c
romstage-y += die.c
+postcar-y += vtxprintf.c printk.c
+postcar-y += init.c console.c
+postcar-y += post.c
+postcar-y += die.c
+
bootblock-$(CONFIG_BOOTBLOCK_CONSOLE) += vtxprintf.c printk.c
bootblock-$(CONFIG_BOOTBLOCK_CONSOLE) += init.c console.c
bootblock-y += die.c
diff --git a/src/cpu/x86/lapic/Makefile.inc b/src/cpu/x86/lapic/Makefile.inc
index c0a35727bb..9df2c5fad1 100644
--- a/src/cpu/x86/lapic/Makefile.inc
+++ b/src/cpu/x86/lapic/Makefile.inc
@@ -7,3 +7,4 @@ bootblock-y += boot_cpu.c
verstage-y += boot_cpu.c
romstage-y += boot_cpu.c
ramstage-y += boot_cpu.c
+postcar-y += boot_cpu.c
diff --git a/src/include/console/console.h b/src/include/console/console.h
index 770489967f..ddb5c0524b 100644
--- a/src/include/console/console.h
+++ b/src/include/console/console.h
@@ -47,7 +47,7 @@ void __attribute__ ((noreturn)) die(const char *msg);
#define __CONSOLE_ENABLE__ \
((ENV_BOOTBLOCK && CONFIG_BOOTBLOCK_CONSOLE) || \
- ENV_VERSTAGE || ENV_ROMSTAGE || ENV_RAMSTAGE || \
+ ENV_VERSTAGE || ENV_ROMSTAGE || ENV_RAMSTAGE || ENV_POSTCAR || \
(ENV_SMM && CONFIG_DEBUG_SMI))
#if __CONSOLE_ENABLE__
diff --git a/src/include/memlayout.h b/src/include/memlayout.h
index 49aa1cc437..43a1caca75 100644
--- a/src/include/memlayout.h
+++ b/src/include/memlayout.h
@@ -160,6 +160,18 @@
#define OVERLAP_VERSTAGE_ROMSTAGE(addr, size) ROMSTAGE(addr, size)
#endif
+#if ENV_POSTCAR
+ #define POSTCAR(addr, sz) \
+ SYMBOL(postcar, addr) \
+ _epostcar = _postcar + sz; \
+ _ = ASSERT(_eprogram - _program <= sz, \
+ STR(Aftercar exceeded its allotted size! (sz))); \
+ INCLUDE "postcar/lib/program.ld"
+#else
+ #define POSTCAR(addr, sz) \
+ REGION(postcar, addr, sz, 1)
+#endif
+
#define WATCHDOG_TOMBSTONE(addr, size) \
REGION(watchdog_tombstone, addr, size, 4) \
_ = ASSERT(size == 4, "watchdog tombstones should be exactly 4 byte!");
diff --git a/src/include/rules.h b/src/include/rules.h
index 6a05ae949c..89fdd21cb2 100644
--- a/src/include/rules.h
+++ b/src/include/rules.h
@@ -26,6 +26,7 @@
#define ENV_SMM 0
#define ENV_VERSTAGE 0
#define ENV_RMODULE 0
+#define ENV_POSTCAR 0
#define ENV_STRING "bootblock"
#elif defined(__ROMSTAGE__)
@@ -35,6 +36,7 @@
#define ENV_SMM 0
#define ENV_VERSTAGE 0
#define ENV_RMODULE 0
+#define ENV_POSTCAR 0
#define ENV_STRING "romstage"
#elif defined(__SMM__)
@@ -44,6 +46,7 @@
#define ENV_SMM 1
#define ENV_VERSTAGE 0
#define ENV_RMODULE 0
+#define ENV_POSTCAR 0
#define ENV_STRING "smm"
#elif defined(__VERSTAGE__)
@@ -53,6 +56,7 @@
#define ENV_SMM 0
#define ENV_VERSTAGE 1
#define ENV_RMODULE 0
+#define ENV_POSTCAR 0
#define ENV_STRING "verstage"
#elif defined(__RAMSTAGE__)
@@ -62,6 +66,7 @@
#define ENV_SMM 0
#define ENV_VERSTAGE 0
#define ENV_RMODULE 0
+#define ENV_POSTCAR 0
#define ENV_STRING "ramstage"
#elif defined(__RMODULE__)
@@ -71,8 +76,19 @@
#define ENV_SMM 0
#define ENV_VERSTAGE 0
#define ENV_RMODULE 1
+#define ENV_POSTCAR 0
#define ENV_STRING "rmodule"
+#elif defined(__POSTCAR__)
+#define ENV_BOOTBLOCK 0
+#define ENV_ROMSTAGE 0
+#define ENV_RAMSTAGE 0
+#define ENV_SMM 0
+#define ENV_VERSTAGE 0
+#define ENV_RMODULE 0
+#define ENV_POSTCAR 1
+#define ENV_STRING "postcar"
+
#else
/*
* Default case of nothing set for random blob generation using
@@ -86,18 +102,21 @@
#define ENV_SMM 0
#define ENV_VERSTAGE 0
#define ENV_RMODULE 0
+#define ENV_POSTCAR 0
#define ENV_STRING "UNKNOWN"
#endif
-/* For romstage and ramstage always build with simple device model, ie.
- * PCI, PNP and CPU functions operate without use of devicetree.
+/* For pre-DRAM stages and post-CAR always build with simple device model, ie.
+ * PCI, PNP and CPU functions operate without use of devicetree. The reason
+ * post-CAR utilizes __SIMPLE_DEVICE__ is for simplicity. Currently there's
+ * no known requirement that devicetree would be needed during that stage.
*
* For ramstage individual source file may define __SIMPLE_DEVICE__
* before including any header files to force that particular source
* be built with simple device model.
*/
-#if defined(__PRE_RAM__) || defined(__SMM__)
+#if defined(__PRE_RAM__) || ENV_SMM || ENV_POSTCAR
#define __SIMPLE_DEVICE__
#endif
diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 646fefab5f..3352a3027f 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -131,13 +131,16 @@ ramstage-$(CONFIG_ACPI_NHLT) += nhlt.c
romstage-y += cbmem_common.c
romstage-y += imd_cbmem.c
+romstage-y += imd.c
ramstage-y += cbmem_common.c
ramstage-y += imd_cbmem.c
-
-romstage-y += imd.c
ramstage-y += imd.c
+postcar-y += cbmem_common.c
+postcar-y += imd_cbmem.c
+postcar-y += imd.c
+
bootblock-y += hexdump.c
ramstage-y += hexdump.c
romstage-y += hexdump.c
@@ -167,12 +170,14 @@ romstage-y += version.c
ramstage-y += version.c
smm-y += version.c
verstage-y += version.c
+postcar-y += version.c
$(call src-to-obj,bootblock,$(dir)/version.c) : $(obj)/build.h
$(call src-to-obj,romstage,$(dir)/version.c) : $(obj)/build.h
$(call src-to-obj,ramstage,$(dir)/version.c) : $(obj)/build.h
$(call src-to-obj,smm,$(dir)/version.c) : $(obj)/build.h
$(call src-to-obj,verstage,$(dir)/version.c) : $(obj)/build.h
+$(call src-to-obj,postcar,$(dir)/version.c) : $(obj)/build.h
romstage-y += bootmode.c
ramstage-y += bootmode.c
@@ -183,9 +188,27 @@ romstage-y += halt.c
ramstage-y += halt.c
smm-y += halt.c
+postcar-y += bootmode.c
+postcar-y += boot_device.c
+postcar-y += cbfs.c
+postcar-$(CONFIG_COMMON_CBFS_SPI_WRAPPER) += cbfs_spi.c
+postcar-y += delay.c
+postcar-y += fmap.c
+postcar-y += gcc.c
+postcar-y += halt.c
+postcar-y += libgcc.c
+postcar-$(CONFIG_COMPRESS_RAMSTAGE) += lzma.c lzmadecode.c
+postcar-y += memchr.c
+postcar-y += memcmp.c
+postcar-y += prog_loaders.c
+postcar-y += prog_ops.c
+postcar-y += rmodule.c
+postcar-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c
+
# Use program.ld for all the platforms which use C fo the bootblock.
bootblock-$(CONFIG_C_ENVIRONMENT_BOOTBLOCK) += program.ld
+postcar-y += program.ld
romstage-y += program.ld
ramstage-y += program.ld
verstage-y += program.ld
diff --git a/src/lib/program.ld b/src/lib/program.ld
index 9b8c7c9ec1..99afe5dd56 100644
--- a/src/lib/program.ld
+++ b/src/lib/program.ld
@@ -80,7 +80,14 @@
. = ALIGN(ARCH_CACHELINE_ALIGN_SIZE);
_data = .;
-#if ENV_RMODULE
+/*
+ * The postcar phase uses a stack value that is located in the relocatable
+ * module section. While the postcar stage could be linked like smm and
+ * other rmodules the postcar stage needs similar semantics of the more
+ * traditional stages in the coreboot infrastructure. Therefore it's easier
+ * to specialize this case.
+ */
+#if ENV_RMODULE || ENV_POSTCAR
_rmodule_params = .;
KEEP(*(.module_parameters));
_ermodule_params = .;