When updating firmware, it is very often that we may want to preserve
few sections, for example vital product data (VPD) including serial
number, calibration data and cache. A firmware updater has to hard-code
the section names that need to be preserved and is hard to maintain.
A better approach is to specify that in FMAP area flags (the `area_flag`
field) using FMAP_AREA_PRESERVE. With this patchset, a FMD parser flag
"PRESERVE" is introduced and will be converted to FMAP_AREA_PRESERVE
when generating FMAP data (by fmap_from_fmd.c).
For example, The FMD statement:
  RO_VPD(PRESERVE)@0x0 16k
will generate an FMAP firmware section that:
  area_name = "RO_VPD"
  area_offset = 0
  area_size = 16384
  area_flags = FMAP_AREA_PRESERVE
BUG=chromium:936768
TEST=make; boots on x86 "google/eve" and arm "google/kukui" devices
     Manually added 'PRESERVE' to some FMD files, and verify (by running
     fmap.py) the output coreboot.rom has FMAP_AREA_PRESERVE set
Change-Id: I51e7d31029b98868a1cab0d26bf04a14db01b1c0
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31707
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
		
	
		
			
				
	
	
		
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			193 lines
		
	
	
		
			4.9 KiB
		
	
	
	
		
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| /*
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|  * fmd_parser.y, parser generator for flashmap descriptor language
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|  *
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|  * Copyright (C) 2015 Google, Inc.
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; version 2 of the License.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  */
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| 
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| %{
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| #include "fmd_scanner.h"
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| #include "common.h"
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| 
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| #include <stdlib.h>
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| 
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| struct flashmap_descriptor *res = NULL;
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| %}
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| 
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| %union {
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| 	unsigned intval;
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| 	char *strval;
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| 	struct unsigned_option maybe_intval;
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| 	struct flashmap_descriptor *region_ptr;
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| 	union flashmap_flags flags;
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| 	struct descriptor_list region_listhdr;
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| }
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| 
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| %code requires {
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| #include "fmd.h"
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| #include "option.h"
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| 
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| #include <stdbool.h>
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| 
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| struct descriptor_node {
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| 	struct flashmap_descriptor *val;
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| 	struct descriptor_node *next;
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| };
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| 
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| struct descriptor_list {
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| 	size_t len;
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| 	struct descriptor_node *head;
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| 	struct descriptor_node *tail;
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| };
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| 
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| extern struct flashmap_descriptor *res;
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| 
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| struct flashmap_descriptor *parse_descriptor(
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| 	char *name, union flashmap_flags flags, struct unsigned_option offset,
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| 	struct unsigned_option size, struct descriptor_list children);
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| void yyerror(const char *s);
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| }
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| 
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| %token <intval> INTEGER
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| %token OCTAL
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| %token <strval> STRING
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| %token FLAG_CBFS
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| %token FLAG_PRESERVE
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| 
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| %type <region_ptr> flash_region
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| %type <strval> region_name
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| %type <flags> region_flags_opt
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| %type <flags> region_flags
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| %type <flags> region_flag
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| %type <maybe_intval> region_offset_opt
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| %type <maybe_intval> region_offset
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| %type <maybe_intval> region_size_opt
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| %type <maybe_intval> region_size
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| %type <region_listhdr> region_list_opt
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| %type <region_listhdr> region_list
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| %type <region_listhdr> region_list_entries
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| 
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| %%
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| 
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| flash_chip: region_name region_offset_opt region_size region_list
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| {
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| 	union flashmap_flags flags = { .v=0 };
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| 	if (!(res = parse_descriptor($1, flags, $2, $3, $4)))
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| 		YYABORT;
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| };
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| flash_region: region_name region_flags_opt region_offset_opt region_size_opt
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| 	      region_list_opt
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| {
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| 	struct flashmap_descriptor *node = parse_descriptor($1, $2, $3, $4, $5);
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| 	if (!node)
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| 		YYABORT;
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| 
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| 	if (node->flags.f.cbfs && !fmd_process_flag_cbfs(node)) {
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| 		ERROR("Section '%s' cannot have flag 'CBFS''\n", node->name);
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| 		YYABORT;
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| 	}
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| 
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| 	$$ = node;
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| };
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| region_name: STRING
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| {
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| 	if (!$1) {
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| 		perror("E: While allocating section name");
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| 		YYABORT;
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| 	}
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| };
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| region_flags_opt: { $$ = (union flashmap_flags){ .v=0 }; }
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| 	| '(' region_flags ')' { $$ = $2; };
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| region_flags: region_flag | region_flag region_flags { $$.v = $1.v | $2.v; };
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| region_flag: FLAG_CBFS { $$.v = 0; $$.f.cbfs = 1; };
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| region_flag: FLAG_PRESERVE { $$.v = 0; $$.f.preserve = 1; };
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| region_offset_opt: { $$ = (struct unsigned_option){false, 0}; }
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| 	| region_offset;
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| region_offset: '@' INTEGER { $$ = (struct unsigned_option){true, $2}; };
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| region_size_opt: { $$ = (struct unsigned_option){false, 0}; }
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| 	| region_size;
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| region_size: INTEGER { $$ = (struct unsigned_option){true, $1}; };
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| region_list_opt:
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| {
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| 	$$ = (struct descriptor_list)
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| 					{.len = 0, .head = NULL, .tail = NULL};
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| }
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| 	| region_list;
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| region_list: '{' region_list_entries '}' { $$ = $2; };
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| region_list_entries: flash_region
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| {
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| 	struct descriptor_node *node = malloc(sizeof(*node));
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| 	if (!node) {
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| 		perror("E: While allocating linked list node");
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| 		YYABORT;
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| 	}
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| 	node->val = $1;
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| 	node->next = NULL;
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| 	$$ = (struct descriptor_list){.len = 1, .head = node, .tail = node};
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| }
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| 	| region_list_entries flash_region
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| {
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| 	struct descriptor_node *node = malloc(sizeof(*node));
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| 	if (!node) {
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| 		perror("E: While allocating linked list node");
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| 		YYABORT;
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| 	}
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| 	node->val = $2;
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| 	node->next = NULL;
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| 
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| 	$1.tail->next = node;
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| 	$$ = (struct descriptor_list)
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| 			{.len = $1.len + 1, .head = $1.head, .tail = node};
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| };
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| 
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| %%
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| 
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| struct flashmap_descriptor *parse_descriptor(
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| 	char *name, union flashmap_flags flags, struct unsigned_option offset,
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| 	struct unsigned_option size, struct descriptor_list children)
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| {
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| 	struct flashmap_descriptor *region = malloc(sizeof(*region));
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| 	if (!region) {
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| 		perror("E: While allocating descriptor section");
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| 		return NULL;
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| 	}
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| 	region->name = name;
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| 	region->flags = flags;
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| 	region->offset_known = offset.val_known;
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| 	region->offset = offset.val;
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| 	region->size_known = size.val_known;
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| 	region->size = size.val;
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| 	region->list_len = children.len;
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| 	if (region->list_len) {
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| 		region->list = malloc(region->list_len * sizeof(*region->list));
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| 		if (!region->list) {
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| 			perror("E: While allocating node children array");
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| 			return NULL;
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| 		}
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| 		struct descriptor_node *cur_node = children.head;
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| 		for (unsigned idx = 0; idx < region->list_len; ++idx) {
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| 			region->list[idx] = cur_node->val;
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| 
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| 			struct descriptor_node *next_node = cur_node->next;
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| 			free(cur_node);
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| 			cur_node = next_node;
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| 		}
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| 	} else {
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| 		region->list = NULL;
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| 	}
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| 	return region;
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| }
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| 
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| void yyerror(const char *s)
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| {
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| 	fprintf(stderr, "%s\n", s);
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| }
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