#define CFG_SYS_SDRAM_BASE      PHYS_SDRAM
#define CFG_SYS_INIT_RAM_ADDR   IRAM_BASE_ADDR
#define CFG_SYS_INIT_RAM_SIZE   IRAM_SIZE

然后在common/pad_f.c上,SDRAM基面地址被分配到用于U-Boot使用的RAM基面地址的全球数据变量上:

static int setup_dest_addr(void)
{
    ...
    gd->ram_base = CFG_SYS_SDRAM_BASE;

委员会信息结构的第一个记忆库后来填充了common/板_f.c的全球数据记忆:

__weak int dram_init_banksize(void)
{
    gd->bd->bi_dram[0].start = gd->ram_base;
    gd->bd->bi_dram[0].size = get_effective_memsize();

    return 0;
}

这是后来用于填充LMB结构(lib/lmb.c)的理事会记忆:

/* Initialize the struct, add memory and call arch/board reserve functions */
void lmb_init_and_reserve(struct lmb *lmb, struct bd_info *bd, void *fdt_blob)
{
    int i;

    lmb_init(lmb);

    for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
        if (bd->bi_dram[i].size) {
            lmb_add(lmb, bd->bi_dram[i].start,
                bd->bi_dram[i].size);
        }
    }

    lmb_reserve_common(lmb, fdt_blob);
}

So the Logical Memory Block "library" relies on U-Boot s legacy method for defining memory.
That means the memory definitions in the Device Tree are ignored by U-Boot.

When you try to load a file from a storage device to memory, the following procedure is called in fs/fs.c

#ifdef CONFIG_LMB
/* Check if a file may be read to the given address */
static int fs_read_lmb_check(const char *filename, ulong addr, loff_t offset,
                 loff_t len, struct fstype_info *info)
{
    ...
    lmb_init_and_reserve(&lmb, gd->bd, (void *)gd->fdt_blob);
    lmb_dump_all(&lmb);

    if (lmb_alloc_addr(&lmb, addr, read_len) == addr)
        return 0;

    log_err("** Reading file would overwrite reserved memory **
");
    return -ENOSPC;
}
#endif

Note the conditional compilation for this routine that performs the memory check.
I tied to build a version of U-Boot 2022.01 without CONFIG_LMB, but the build failed. So even though CONFIG_LMB appears to be an optional library selection in the menuconfig, there seems to be source code changes needed to de-select CONFIG_LMB.
So you cannot try to bypass this memory check by building an alternate configuration of U-Boot.

A Workaround

Rather than try to define the aux memory as a bank of main memory, there is a simple & easy workaround to use a recent & unmodified U-Boot in your situation. Instead of loading the file directly to the auxiliary processor memory, simply load the file to main memory at 0x80008000, and then perform a copy of 32KB to the aux memory at tcm_addr.
The loadm4image variable should be changed to:

loadm4image=fatload mmc ${mmcdev}:${mmcpart} 80008000 ${m4image}; 
cp.b 80008000 ${tcm_addr} 8000

This can be accomplished with the following command to the previously posted environment:

setenv loadm4image  fatload mmc ${mmcdev}:${mmcpart} 80008000 ${m4image}; cp.b 80008000 ${tcm_addr} 8000