OVMS3-idf/components/soc/src/memory_layout_utils.c

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// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <stdint.h>
#include <string.h>
#include "esp_log.h"
#include "soc/soc_memory_layout.h"
static const char *TAG = "memory_layout";
/* These variables come from the linker script,
delimit the start and end of entries created via
SOC_RESERVE_MEMORY_REGION() macro.
*/
extern soc_reserved_region_t soc_reserved_memory_region_start;
extern soc_reserved_region_t soc_reserved_memory_region_end;
/*
These variables have the start and end of the data and static IRAM
area used by the program. Defined in the linker script.
*/
extern int _data_start, _static_data_end, _iram_start, _iram_end;
/* static DRAM & IRAM chunks */
static const size_t EXTRA_RESERVED_REGIONS = 2;
static size_t s_get_num_reserved_regions(void)
{
return ( ( &soc_reserved_memory_region_end
- &soc_reserved_memory_region_start ) +
EXTRA_RESERVED_REGIONS );
}
size_t soc_get_available_memory_region_max_count(void)
{
/* Worst-case: each reserved memory region splits an available
region in two, so the maximum possible number of regions
is the number of regions of memory plus the number of reservations */
return soc_memory_region_count + s_get_num_reserved_regions();
}
static int s_compare_reserved_regions(const void *a, const void *b)
{
const soc_reserved_region_t *r_a = (soc_reserved_region_t *)a;
const soc_reserved_region_t *r_b = (soc_reserved_region_t *)b;
return (int)r_a->start - (int)r_b->start;
}
/* Initialize a mutable array of reserved regions in 'reserved',
then sort it by start address and check for overlapping
reserved regions (illegal).
*/
static void s_prepare_reserved_regions(soc_reserved_region_t *reserved, size_t count)
{
memcpy(reserved + EXTRA_RESERVED_REGIONS,
&soc_reserved_memory_region_start,
(count - EXTRA_RESERVED_REGIONS) * sizeof(soc_reserved_region_t));
/* Add the EXTRA_RESERVED_REGIONS at the beginning */
reserved[0].start = (intptr_t)&_data_start; /* DRAM used by data+bss */
reserved[0].end = (intptr_t)&_static_data_end;
reserved[1].start = (intptr_t)&_iram_start; /* IRAM used by code */
reserved[1].end = (intptr_t)&_iram_end;
/* Sort by starting address */
qsort(reserved, count, sizeof(soc_reserved_region_t), s_compare_reserved_regions);
/* Validity checks */
ESP_EARLY_LOGV(TAG, "reserved range is %p - %p",
&soc_reserved_memory_region_start,
&soc_reserved_memory_region_end);
ESP_EARLY_LOGD(TAG, "Checking %d reserved memory ranges:", count);
for (size_t i = 0; i < count; i++)
{
ESP_EARLY_LOGD(TAG, "Reserved memory range 0x%08x - 0x%08x",
reserved[i].start, reserved[i].end);
reserved[i].start = reserved[i].start & ~3; /* expand all reserved areas to word boundaries */
reserved[i].end = (reserved[i].end + 3) & ~3;
assert(reserved[i].start < reserved[i].end);
if (i < count - 1) {
assert(reserved[i+1].start > reserved[i].start);
if (reserved[i].end > reserved[i+1].start) {
ESP_EARLY_LOGE(TAG, "SOC_RESERVE_MEMORY_REGION region range " \
"0x%08x - 0x%08x overlaps with 0x%08x - 0x%08x",
reserved[i].start, reserved[i].end, reserved[i+1].start,
reserved[i+1].end);
abort();
}
}
}
}
size_t soc_get_available_memory_regions(soc_memory_region_t *regions)
{
soc_memory_region_t *out_region = regions;
/* make a local copy of the "input" regions so we can modify them */
soc_memory_region_t in_regions[soc_memory_region_count];
memcpy(in_regions, soc_memory_regions, sizeof(in_regions));
soc_memory_region_t *in_region = in_regions;
size_t num_reserved = s_get_num_reserved_regions();
soc_reserved_region_t reserved[num_reserved];
s_prepare_reserved_regions(reserved, num_reserved);
/* Go through the "in" regions (full regions, with no reserved
sections removed from them) one at a time, trim off each reserved
region, and then copy them to an out_region once trimmed
*/
ESP_EARLY_LOGD(TAG, "Building list of available memory regions:");
while(in_region != in_regions + soc_memory_region_count) {
soc_memory_region_t in = *in_region;
ESP_EARLY_LOGV(TAG, "Examining memory region 0x%08x - 0x%08x", in.start, in.start + in.size);
intptr_t in_start = in.start;
intptr_t in_end = in_start + in.size;
bool copy_in_to_out = true;
bool move_to_next = true;
for (size_t i = 0; i < num_reserved; i++) {
if (reserved[i].start >= SOC_DRAM_HIGH && in_end < SOC_DRAM_HIGH && in.iram_address != 0) {
reserved[i].start = reserved[i].start - (in.iram_address - in.start);
reserved[i].end = reserved[i].end - (in.iram_address - in.start);
}
if (reserved[i].end <= in_start || reserved[i].start >= in_end) {
/* reserved region ends before 'in' starts or reserved region starts after 'in' ends */
continue;
}
else if (reserved[i].start <= in_start &&
reserved[i].end >= in_end) { /* reserved covers all of 'in' */
ESP_EARLY_LOGV(TAG, "Region 0x%08x - 0x%08x inside of reserved 0x%08x - 0x%08x",
in_start, in_end, reserved[i].start, reserved[i].end);
/* skip 'in' entirely */
copy_in_to_out = false;
break;
}
else if (in_start < reserved[i].start &&
in_end > reserved[i].end) { /* reserved contained inside 'in', need to "hole punch" */
ESP_EARLY_LOGV(TAG, "Region 0x%08x - 0x%08x contains reserved 0x%08x - 0x%08x",
in_start, in_end, reserved[i].start, reserved[i].end);
assert(in_start < reserved[i].start);
assert(in_end > reserved[i].end);
/* shrink this region to end where the reserved section starts */
in_end = reserved[i].start;
in.size = in_end - in_start;
/* update in_region so the 'next' iteration uses the region
after the reserved section */
in_region->size -= (reserved[i].end - in_region->start);
in_region->start = reserved[i].end;
/* add first region, then re-run while loop with the updated in_region */
move_to_next = false;
break;
}
else if (reserved[i].start <= in_start) { /* reserved overlaps start of 'in' */
ESP_EARLY_LOGV(TAG, "Start of region 0x%08x - 0x%08x overlaps reserved 0x%08x - 0x%08x",
in_start, in_end, reserved[i].start, reserved[i].end);
in.start = reserved[i].end;
in_start = in.start;
in.size = in_end - in_start;
}
else { /* reserved overlaps end of 'in' */
ESP_EARLY_LOGV(TAG, "End of region 0x%08x - 0x%08x overlaps reserved 0x%08x - 0x%08x",
in_start, in_end, reserved[i].start, reserved[i].end);
in_end = reserved[i].start;
in.size = in_end - in_start;
}
}
if (copy_in_to_out) {
ESP_EARLY_LOGD(TAG, "Available memory region 0x%08x - 0x%08x", in.start, in.start + in.size);
*out_region++ = in;
}
if (move_to_next) {
in_region++;
}
}
return (out_region - regions); /* return number of regions */
}