客户：我们将使用 AM6548 SR2.0 来启动 EVM 板，届时 EVM 中将有 2 个 512MB、总共 1GB 的 DDR4。
在这种情况下，我们有两个问题需要与您确认。
1.如何修改 k3-am654-board-board.dts 中的存储区？SDK 的默认值为 4G。
memory@80000000 {
device_type = "memory";
/* 4G RAM */
reg = <0x00000000 0x80000000 0x00000000 0x80000000>,
<0x00000008 0x80000000 0x00000000 0x80000000>;
};
2.在 evm.c 中，我们按如下方式修改 ram_size，正确吗？我不确定是否需要设置 gd->bd->bi_dram[1] 。
int dram_init(void)
{
#ifdef CONFIG_PHYS_64BIT
gd->ram_size = 0x40000000;//ERIC*
#else
gd->ram_size = 0x80000000;
#endif
return 0;
}
ulong board_get_usable_ram_top(ulong total_size)
{
#ifdef CONFIG_PHYS_64BIT
/* 将 U-Boot 使用的 RAM 限制为 DDR 低位区域 */
if (gd->ram_top > 0x40000000)
return 0x40000000;
#endif
return gd->ram_top;
}
int dram_init_banksize(void)
{
/* 组 0 声明 DDR 低位区域中可用 内存*/
gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
gd->bd->bi_dram[0].size = 0x40000000;
gd->ram_size = 0x40000000;
#ifdef CONFIG_PHYS_64BIT
/* 组 1 声明 DDR 高位区域中可用内存 */
gd->bd->bi_dram[1].start = CONFIG_SYS_SDRAM_BASE1;
gd->bd->bi_dram[1].size = 0x40000000;//ERIC*
gd->ram_size = 0x40000000;//ERIC*
#endif
return 0;
答案：这是不是从 0x80000000 开始的连续 1GB 空间？
客户：是的，它将是连续的 1GB 空间。并且带宽为 16 bit*2。
答案：这是我将 AM654 存储器减少到 1GB 时使用的 diff 命令。
diff --git a/arch/arm/dts/k3-am654-base-board.dts b/arch/arm/dts/k3-am654-base-board.dts
index afa7b5a353..e13eac4c15 100644
--- a/arch/arm/dts/k3-am654-base-board.dts
+++ b/arch/arm/dts/k3-am654-base-board.dts
@@ -24,9 +24,8 @@
memory@80000000 {
device_type = "memory";
- /* 4G RAM */
- reg = <0x00000000 0x80000000 0x00000000 0x80000000>,
- <0x00000008 0x80000000 0x00000000 0x80000000>;
+ /* 1G RAM */
+ reg = <0x00000000 0x80000000 0x00000000 0x40000000>;
};
reserved-memory {
diff --git a/arch/arm/mach-k3/arm64-mmu.c b/arch/arm/mach-k3/arm64-mmu.c
index a0da3df593..d708c97f70 100644
--- a/arch/arm/mach-k3/arm64-mmu.c
+++ b/arch/arm/mach-k3/arm64-mmu.c
@@ -44,12 +44,6 @@ struct mm_region am654_mem_map[NR_MMU_REGIONS] = {
.size = 0x5df00000UL,
.attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
PTE_BLOCK_INNER_SHARE
- }, {
- .virt = 0x880000000UL,
- .phys = 0x880000000UL,
- .size = 0x80000000UL,
- .attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) |
- PTE_BLOCK_INNER_SHARE
}, {
.virt = 0x500000000UL,
.phys = 0x500000000UL,
diff --git a/board/ti/am65x/evm.c b/board/ti/am65x/evm.c
index 045a43c498..9b6c969528 100644
--- a/board/ti/am65x/evm.c
+++ b/board/ti/am65x/evm.c
@@ -77,11 +77,7 @@ int board_init(void)
int dram_init(void)
{
-#ifdef CONFIG_PHYS_64BIT
- gd->ram_size = 0x100000000;
-#else
- gd->ram_size = 0x80000000;
-#endif
+ gd->ram_size = 0x40000000;
return 0;
}
@@ -101,15 +97,8 @@ int dram_init_banksize(void)
{
/* 组 0 声明 DDR 低位区域中可用内存 */
gd->bd->bi_dram[0].start = CONFIG_SYS_SDRAM_BASE;
- gd->bd->bi_dram[0].size = 0x80000000;
- gd->ram_size = 0x80000000;
-
-#ifdef CONFIG_PHYS_64BIT
- /* 组 1 声明 DDR 高位区域中可用内存*/
- gd->bd->bi_dram[1].start = CONFIG_SYS_SDRAM_BASE1;
- gd->bd->bi_dram[1].size = 0x80000000;
- gd->ram_size = 0x100000000;
-#endif
+ gd->bd->bi_dram[0].size = 0x40000000;
+ gd->ram_size = 0x40000000;
return 0;
}
diff --git a/configs/am65x_evm_a53_defconfig b/configs/am65x_evm_a53_defconfig
index 93e539aba5..a08889b5ff 100644
--- a/configs/am65x_evm_a53_defconfig
+++ b/configs/am65x_evm_a53_defconfig
@@ -12,7 +12,7 @@ CONFIG_SPL_DRIVERS_MISC_SUPPORT=y
CONFIG_ENV_SIZE=0x20000
CONFIG_ENV_OFFSET=0x680000
CONFIG_SPL_STACK_R_ADDR=0x82000000
-CONFIG_NR_DRAM_BANKS=2
+CONFIG_NR_DRAM_BANKS=1
CONFIG_SPL_FS_FAT=y
CONFIG_SPL_LIBDISK_SUPPORT=y
CONFIG_SPL_SPI_FLASH_SUPPORT=y
diff --git a/include/configs/am65x_evm.h b/include/configs/am65x_evm.h
index 41c62785e4..f7ca664cd9 100644
--- a/include/configs/am65x_evm.h
+++ b/include/configs/am65x_evm.h
@@ -15,9 +15,6 @@
#include <environment/ti/k3_rproc.h>
#include <environment/ti/k3_dfu.h>
-/* DDR 配置 */
-#define CONFIG_SYS_SDRAM_BASE1 0x880000000
-
/* SPL 加载程序配置 */
#ifdef CONFIG_TARGET_AM654_A53_EVM
#define CONFIG_SYS_INIT_SP_ADDR (CONFIG_SPL_TEXT_BASE + \
通过上述补丁，我可以看到 u-boot 可识别到 1GB。
U-Boot 2020.01-dirty (Mar 11 2021 - 13:02:48 +0530)
SoC: AM65X SR2.0
Model: Texas Instruments AM654 Base Board
Board: AM6-COMPROCEVM rev A
DRAM: 1 GiB
MMC: sdhci@4f80000: 0, sdhci@4fa0000: 1
Loading Environment from MMC...OK
In: serial
Out: serial
Err: serial
Detected: AM6-IDKAPPEVM rev A
Detected: SER-PCIE2LEVM rev A
Net:
Warning: ethernet@46000000 using MAC address from ROM
eth0: ethernet@46000000
客户：我已经在 TI AM654 EVM 板上验证了该解决方案是有效的。
