From: Michel Pollet <buserror@gmail.com>
Date: Mon, 12 Aug 2013 10:31:57 +0000 (+0100)
Subject: elf: Redone the symbol loader
X-Git-Tag: v1.1~8
X-Git-Url: https://git.htl-mechatronik.at/public/?a=commitdiff_plain;h=ccb3592f51c9333b9332c59102c11eae61c973c0;p=sx%2Fsimavr.git

elf: Redone the symbol loader

Old symbol loader had been geared for the 'trace' functionality, and was
partitularly bad since it didnt know the size of the code it was
loading.

New version loads a (sorted) array of symbols, and let the firmware
loader code deal with the old 'codeline' array. The new loaded symbol
table can be used separately (board code can look into it).

Also changed the avr_symbol_t to inline the symbol name, instead of
using a separate pointer.

Signed-off-by: Michel Pollet <buserror@gmail.com>
---

diff --git a/simavr/sim/sim_avr.h b/simavr/sim/sim_avr.h
index f391902..dde8873 100644
--- a/simavr/sim/sim_avr.h
+++ b/simavr/sim/sim_avr.h
@@ -298,8 +298,8 @@ typedef struct avr_kind_t {
 
 // a symbol loaded from the .elf file
 typedef struct avr_symbol_t {
-	const char * symbol;
 	uint32_t	addr;
+	const char  symbol[0];
 } avr_symbol_t;
 
 // locate the maker for mcu "name" and allocates a new avr instance
diff --git a/simavr/sim/sim_elf.c b/simavr/sim/sim_elf.c
index af4ab2d..37cd653 100644
--- a/simavr/sim/sim_elf.c
+++ b/simavr/sim/sim_elf.c
@@ -50,8 +50,23 @@ void avr_load_firmware(avr_t * avr, elf_firmware_t * firmware)
 		avr->avcc = firmware->avcc;
 	if (firmware->aref)
 		avr->aref = firmware->aref;
-#if CONFIG_SIMAVR_TRACE
-	avr->trace_data->codeline = firmware->codeline;
+#if CONFIG_SIMAVR_TRACE && ELF_SYMBOLS
+	int scount = firmware->flashsize >> 1;
+	avr->trace_data->codeline = malloc(scount * sizeof(avr_symbol_t*));
+	memset(avr->trace_data->codeline, 0, scount * sizeof(avr_symbol_t*));
+
+	for (int i = 0; i < firmware->symbolcount; i++)
+		if (!(firmware->symbol[i]->addr >> 20))	// code address
+			avr->trace_data->codeline[firmware->symbol[i]->addr >> 1] = 
+				firmware->symbol[i];
+	// "spread" the pointers for known symbols forward
+	avr_symbol_t * last = NULL;
+	for (int i = 0; i < scount; i++) {
+		if (!avr->trace_data->codeline[i])
+			avr->trace_data->codeline[i] = last;
+		else
+			last = avr->trace_data->codeline[i];
+	}
 #endif
 
 	avr_loadcode(avr, firmware->flash, firmware->flashsize, firmware->flashbase);
@@ -199,11 +214,8 @@ int elf_read_firmware(const char * file, elf_firmware_t * firmware)
 
 	memset(firmware, 0, sizeof(*firmware));
 #if ELF_SYMBOLS
-	//int bitesize = ((avr->flashend+1) >> 1) * sizeof(avr_symbol_t);
-	firmware->codesize = 32768;
-	int bitesize = firmware->codesize * sizeof(avr_symbol_t);
-	firmware->codeline = malloc(bitesize);
-	memset(firmware->codeline,0, bitesize);
+	firmware->symbolcount = 0;
+	firmware->symbol = NULL;
 #endif
 
 	/* this is actually mandatory !! otherwise elf_begin() fails */
@@ -254,37 +266,37 @@ int elf_read_firmware(const char * file, elf_firmware_t * firmware)
 				gelf_getsym(edata, i, &sym);
 
 				// print out the value and size
-			//	printf("%08x %08d ", sym.st_value, sym.st_size);
 				if (ELF32_ST_BIND(sym.st_info) == STB_GLOBAL || 
 						ELF32_ST_TYPE(sym.st_info) == STT_FUNC || 
 						ELF32_ST_TYPE(sym.st_info) == STT_OBJECT) {
 					const char * name = elf_strptr(elf, shdr.sh_link, sym.st_name);
 
-					// type of symbol
-					if (sym.st_value & 0xfff00000) {
-
-					} else {
-						// code
-						if (firmware->codeline[sym.st_value >> 1] == NULL) {
-							avr_symbol_t * s = firmware->codeline[sym.st_value >> 1] = malloc(sizeof(avr_symbol_t));
-							s->symbol = strdup(name);
-							s->addr = sym.st_value;
-						}
-					}
+					avr_symbol_t * s = malloc(sizeof(avr_symbol_t) + strlen(name) + 1);
+					strcpy((char*)s->symbol, name);
+					s->addr = sym.st_value;
+					if (!(firmware->symbolcount % 8))
+						firmware->symbol = realloc(
+							firmware->symbol, 
+							(firmware->symbolcount + 8) * sizeof(firmware->symbol[0]));
+					
+					// insert new element, keep the array sorted
+					int insert = -1;
+					for (int si = 0; si < firmware->symbolcount && insert == -1; si++)
+						if (firmware->symbol[si]->addr >= s->addr)
+							insert = si;
+					if (insert == -1)
+						insert = firmware->symbolcount;
+					else
+						memmove(firmware->symbol + insert + 1, 
+								firmware->symbol + insert,
+								(firmware->symbolcount - insert) * sizeof(firmware->symbol[0]));
+					firmware->symbol[insert] = s;					
+					firmware->symbolcount++;
 				}
 			}
 		}
 #endif
 	}
-#if ELF_SYMBOLS
-	avr_symbol_t * last = NULL;
-	for (int i = 0; i < firmware->codesize; i++) {
-		if (!firmware->codeline[i])
-			firmware->codeline[i] = last;
-		else
-			last = firmware->codeline[i];
-	}
-#endif
 	uint32_t offset = 0;
 	firmware->flashsize =
 			(data_text ? data_text->d_size : 0) +
diff --git a/simavr/sim/sim_elf.h b/simavr/sim/sim_elf.h
index ed760d5..d91b0e5 100644
--- a/simavr/sim/sim_elf.h
+++ b/simavr/sim/sim_elf.h
@@ -68,8 +68,8 @@ typedef struct elf_firmware_t {
 	uint32_t 	eesize;
 
 #if ELF_SYMBOLS
-	avr_symbol_t **  codeline;
-	uint32_t		codesize;	// in elements
+	avr_symbol_t **  symbol;
+	uint32_t		symbolcount;
 #endif
 } elf_firmware_t ;