Aaron Durbin has submitted this change. ( https://review.coreboot.org/c/coreboot/+/35035 )
Change subject: arch/x86: Implement RESET_VECTOR_IN_RAM ......................................................................
arch/x86: Implement RESET_VECTOR_IN_RAM
Add support for devices with the reset vector pointing into DRAM. This is a specific implementation that assumes a paradigm of AMD Family 17h (a.k.a. "Zen"). Until the first ljmpl for protected mode, the core's state appears to software like other designs, and then the actual physical addressing becomes recognizable.
These systems cannot implement cache-as-RAM as in more traditional x86 products. Therefore instead of reusing CAR names and variables, a substitute called "earlyram" is introduced. This change makes adjustments to CAR-aware files accordingly.
Enable NO_XIP_EARLY_STAGES. The first stage is already in DRAM, and running subsequent stages as XIP in the boot device would reduce performance.
Finally, add a new early_ram.ld linker file. Because all stages run in DRAM, they can be linked with their .data and .bss as normal, i.e. they don't need to rely on storage available only at a fixed location like CAR systems. The primary purpose of the early_ram.ld is to provide consistent locations for PRERAM_CBMEM_CONSOLE, TIMESTAMP regions, etc. across stages until cbmem is brought online.
BUG=b:147042464 TEST=Build for trembyle, and boot to ramstage. $ objdump -h cbfs/fallback/bootblock.debug Idx ,Name ,Size ,VMA ,LMA ,File off Algn 0 ,.text ,000074d0 ,08076000 ,08076000 ,00001000 2**12 1 ,.data ,00000038 ,0807d4d0 ,0807d4d0 ,000084d0 2**2 2 ,.bss ,00000048 ,0807d508 ,0807d508 ,00008508 2**2 3 ,.stack ,00000800 ,0807daf0 ,0807daf0 ,00000000 2**0 4 ,.persistent ,00001cfa ,0807e2f0 ,0807e2f0 ,00000000 2**0 5 ,.reset ,00000010 ,0807fff0 ,0807fff0 ,0000aff0 2**0 6 ,.debug_info ,0002659c ,00000000 ,00000000 ,0000b000 2**0 7 ,.debug_abbrev ,000074a2 ,00000000 ,00000000 ,0003159c 2**0 8 ,.debug_aranges,00000dd0 ,00000000 ,00000000 ,00038a40 2**3 9 ,.debug_line ,0000ad65 ,00000000 ,00000000 ,00039810 2**0 10 ,.debug_str ,00009655 ,00000000 ,00000000 ,00044575 2**0 11 ,.debug_loc ,0000b7ce ,00000000 ,00000000 ,0004dbca 2**0 12 ,.debug_ranges ,000029c0 ,00000000 ,00000000 ,00059398 2**3
Change-Id: I9c084ff6fdcf7e9154436f038705e8679daea780 Signed-off-by: Marshall Dawson marshalldawson3rd@gmail.com Reviewed-on: https://review.coreboot.org/c/coreboot/+/35035 Reviewed-by: Aaron Durbin adurbin@chromium.org Reviewed-by: Furquan Shaikh furquan@google.com Tested-by: build bot (Jenkins) no-reply@coreboot.org --- M src/arch/x86/Kconfig M src/arch/x86/assembly_entry.S A src/arch/x86/early_ram.ld M src/arch/x86/include/arch/memlayout.h M src/arch/x86/memlayout.ld M src/cpu/Kconfig M src/include/memlayout.h 7 files changed, 69 insertions(+), 5 deletions(-)
Approvals: build bot (Jenkins): Verified Aaron Durbin: Looks good to me, approved Furquan Shaikh: Looks good to me, approved
diff --git a/src/arch/x86/Kconfig b/src/arch/x86/Kconfig index 21107aa..11733bd 100644 --- a/src/arch/x86/Kconfig +++ b/src/arch/x86/Kconfig @@ -89,9 +89,10 @@ config RESET_VECTOR_IN_RAM bool depends on ARCH_X86 + select NO_XIP_EARLY_STAGES help - Select this option if the x86 soc implements custom code to handle the - reset vector in RAM instead of the traditional 0xfffffff0 location. + Select this option if the x86 processor's reset vector is in + preinitialized DRAM instead of the traditional 0xfffffff0 location.
# Aligns 16bit entry code in bootblock so that hyper-threading CPUs # can boot AP CPUs to enable their shared caches. @@ -206,6 +207,7 @@ config POSTCAR_STAGE def_bool y depends on ARCH_X86 + depends on !RESET_VECTOR_IN_RAM
config VERSTAGE_DEBUG_SPINLOOP bool diff --git a/src/arch/x86/assembly_entry.S b/src/arch/x86/assembly_entry.S index f36e7da..59b34c8 100644 --- a/src/arch/x86/assembly_entry.S +++ b/src/arch/x86/assembly_entry.S @@ -9,6 +9,13 @@ * continue with C code execution one needs to set stack pointer and * clear .bss variables that are stage specific. */ + +#if CONFIG(RESET_VECTOR_IN_RAM) + #define _STACK_TOP _eearlyram_stack +#else + #define _STACK_TOP _ecar_stack +#endif + .section ".text._start", "ax", @progbits .global _start _start: @@ -16,8 +23,8 @@ /* Migrate GDT to this text segment */ call gdt_init
- /* reset stack pointer to CAR stack */ - mov $_ecar_stack, %esp + /* reset stack pointer to CAR/EARLYRAM stack */ + mov $_STACK_TOP, %esp
/* clear .bss section as it is not shared */ cld diff --git a/src/arch/x86/early_ram.ld b/src/arch/x86/early_ram.ld new file mode 100644 index 0000000..941c385 --- /dev/null +++ b/src/arch/x86/early_ram.ld @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* This file is part of the coreboot project. */ + +/* This file is included inside a SECTIONS block */ + +_STACK_SIZE = CONFIG_EARLYRAM_BSP_STACK_SIZE; +_ = ASSERT(_STACK_SIZE > 0x0, "EARLYRAM_BSP_STACK_SIZE is not configured"); + +_CONSOLE_SIZE = CONFIG_PRERAM_CBMEM_CONSOLE_SIZE; +_ = ASSERT(_CONSOLE_SIZE > 0x0, "PRERAM_CBMEM_CONSOLE_SIZE is not configured"); + +_TIMESTAMPS_SIZE = 0x200; +#if !CONFIG(NO_FMAP_CACHE) +_FMAP_SIZE = FMAP_SIZE; +#else +_FMAP_SIZE = 0; +#endif + +/* + * The PRERAM_CBMEM_CONSOLE, TIMESTAMP, and FMAP_CACHE regions are shared + * between the pre-ram stages (bootblock, romstage, etc). We need to assign a + * fixed size and consistent link address so they can be shared between stages. + * + * The stack area is not shared between stages, but is defined here for + * convenience. + */ +. = CONFIG_X86_RESET_VECTOR - ARCH_STACK_ALIGN_SIZE - _STACK_SIZE - _CONSOLE_SIZE - _TIMESTAMPS_SIZE - _FMAP_SIZE; + +_ = ASSERT(. > _eprogram, "Not enough room for .earlyram.data. Try increasing C_ENV_BOOTBLOCK_SIZE, or decreasing either EARLYRAM_BSP_STACK_SIZE or PRERAM_CBMEM_CONSOLE_SIZE."); + +.stack ALIGN(ARCH_STACK_ALIGN_SIZE) (NOLOAD) : { + EARLYRAM_STACK(., _STACK_SIZE) +} + +.persistent ALIGN(ARCH_POINTER_ALIGN_SIZE) (NOLOAD) : { + PRERAM_CBMEM_CONSOLE(., _CONSOLE_SIZE) + TIMESTAMP(., _TIMESTAMPS_SIZE) + #if !CONFIG(NO_FMAP_CACHE) + FMAP_CACHE(., FMAP_SIZE) + #endif +} + +_ = ASSERT(. <= CONFIG_X86_RESET_VECTOR, "Earlyram data regions don't fit below the reset vector!"); diff --git a/src/arch/x86/include/arch/memlayout.h b/src/arch/x86/include/arch/memlayout.h index 2eea83f..34d1bd2 100644 --- a/src/arch/x86/include/arch/memlayout.h +++ b/src/arch/x86/include/arch/memlayout.h @@ -8,4 +8,7 @@ # error "CONFIG_RAMTOP not configured" #endif
+/* Intel386 psABI requires a 16 byte aligned stack. */ +#define ARCH_STACK_ALIGN_SIZE 16 + #endif /* __ARCH_MEMLAYOUT_H */ diff --git a/src/arch/x86/memlayout.ld b/src/arch/x86/memlayout.ld index 5e1ef24..31767b3 100644 --- a/src/arch/x86/memlayout.ld +++ b/src/arch/x86/memlayout.ld @@ -9,7 +9,7 @@ #if ENV_CACHE_AS_RAM #define EARLY_MEMLAYOUT "car.ld" #else -#error "Early DRAM environment for x86 is work-in-progress. */ +#define EARLY_MEMLAYOUT "early_ram.ld" #endif #endif
@@ -53,7 +53,9 @@ /* Bootblock specific scripts which provide more SECTION directives. */ #include <cpu/x86/16bit/entry16.ld> #include <cpu/x86/16bit/reset16.ld> +#if !CONFIG(RESET_VECTOR_IN_RAM) #include <arch/x86/id.ld> +#endif #if CONFIG(CPU_INTEL_FIRMWARE_INTERFACE_TABLE) #include <cpu/intel/fit/fit.ld> #endif diff --git a/src/cpu/Kconfig b/src/cpu/Kconfig index c1b84f9..933e50f 100644 --- a/src/cpu/Kconfig +++ b/src/cpu/Kconfig @@ -15,6 +15,10 @@ config DCACHE_BSP_STACK_SIZE hex
+config EARLYRAM_BSP_STACK_SIZE + depends on RESET_VECTOR_IN_RAM + hex + config SMP bool default y if MAX_CPUS != 1 diff --git a/src/include/memlayout.h b/src/include/memlayout.h index bef3637..af277ea 100644 --- a/src/include/memlayout.h +++ b/src/include/memlayout.h @@ -58,6 +58,9 @@ #define PRERAM_CBMEM_CONSOLE(addr, size) \ REGION(preram_cbmem_console, addr, size, 4)
+#define EARLYRAM_STACK(addr, size) \ + REGION(earlyram_stack, addr, size, ARCH_STACK_ALIGN_SIZE) + /* Use either CBFS_CACHE (unified) or both (PRERAM|POSTRAM)_CBFS_CACHE */ #define CBFS_CACHE(addr, size) \ REGION(cbfs_cache, addr, size, 4) \