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A two-component design (Cortex-M + external RAM) is a possibility for chips that have on-chip non-volatile (Flash) memory, which can be used as a storage for the bootloader and uClinux images. There is no on-chip Flash in i.MX RT1050RT10XX, so a three-component design (Cortex-M + external non-volatile memory + external RAM) is the only possibility. However, thanks to the i.MX RT1050 RT10XX internal bootloader (located in a small on-chip ROM) you may select from different types of boot devices. You may boot from: SD/MMC card, serial NOR/NAND Flash, etc.
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On a practical side of things, and given the specific context of SDRAM memory used with the advanced i.MX RT1050 RT10XX microcontrollers, the BOM differences between compatible 16 MB and 32 MB devices are often times quite tolerable. Again, the advice we can give is to play safely and plan for more RAM rather than less.
With that background in mind, here are below is some footprint numbers for a sample Linux configuration that Emcraft includes in the software distribution. The . This project is called hello (for "Hello, world") and can be found in the projects/hello directory, relative to the top of the distribution directory.
The kernel configuration of this project is minimalistic, for instance, the TCP/IP stack is disabled. At the application level, this is really a single-process configuration. Specifically, instead of the standard Linux init, the project runs a custom application called hello. The following are relevant snippets from the hello.intramfs specification file that illustrate how the custom application is installed on the target instead of init.
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file /bin/hello ${INSTALL_ROOT}/projects/${SAMPLE}/hello/hello 755 0 0 |
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slink /init /bin/hello 777 0 0 |
The application itself is a simple endless-loop Hello, world C program, except that before entering the loop it prints the content of /proc/meminfo to stdout (which is the Linux serial console in this specific configuration). The meminfo printout gives information on how much memory is available when the application is running.
The application source can be found in projects/hello/hello/hello.c. For the sake of completeness, here is the full source of that program:
| Code Block | ||
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#include <stdio.h> |
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#include <unistd.h> |
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#include "hello.h" |
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#include <sys/mount.h> |
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int main(int argc, char **argv) |
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{ char buff[4096]; |
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int rc; FILE *fp; printf("Mounting /proc..\\n"); |
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if (mount("proc", "/proc", "proc", MS_MGC_VAL, NULL)) |
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{ perror("Unable to mount /proc"); |
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goto xit; } if (!(fp = fopen("/proc/meminfo", "r"))) |
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{ perror("fopen"); |
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goto xit; } printf("Reading /proc/meminfo:\\n"); |
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while (fgets(buff, sizeof(buff), fp)) |
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{ fputs(buff, stdout); |
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} printf("Done\\n"); |
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while(1) |
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{ printf(HELLO_STRING); |
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sleep(3); |
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} xit: return -1; |
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} |
The bootable Linux image ready for installation to non-volatile storage (SD Card) of the i.MX RT1050 RT10XX (hello.uImage) is ~4~3.7 3 MBytes in size. This is a multi-file Image: ~4 ~3.2 MBytes is the kernel Image itself, and ~7~11.4 5 KBytes is the Device Tree Blob file.
Here is a snapshot of the boot session for that configuration, as run on the i.MX RT1050 EVKRT10XX EVKB. The kernel runs from SD card and is quite fast (note the 1196 BogoMIPS metrics in the kernel output)the network. Boot time to the application (from the point where U-Boot passes control to the kernel) is less than a second. Notice the 23660KBytes 23332 KBytes of unused memory:
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=> run mmcbootnetboot 4836822Using bytesethernet@402d8000 readdevice inTFTP 860from ms (5.4 MiB/s) ## Booting kernel from Legacy Image at 80007fc0 ... Image Name: Linux-5.15.71 Image Type: ARM Linux Multi-File Image (uncompressed) Data Size: 4836758 Bytes = 4.6 MiB Load Address: 80008000 Entry Point: 80008001 Contents:server 192.168.1.89; our IP address is 192.168.1.82 Filename 'imxrt1060/hello.uImage'. Load address: 0x80007fc0 Loading: ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# ################################################################# Image 0: 4829216 Bytes = 4.6 MiB ################################################################# Image 1: 7530 Bytes = 7.4 KiB################################################################# Verifying Checksum ... OK ## Flattened Device################################################################# Tree from multi component Image at 80007FC0 ################################################################# Booting using the fdt at 0x804a302c Loading################################################## Multi-File Image Loading Device Tree to 81e81000, end 81e85d69 ... OK Starting kernel ... Booting Linux on physical CPU 0x0 Linux version 5.15.71 (sasha@workbench.emcraft.com) (arm-none-eabi-gcc (GNU Arm Embedded Toolchain 10.3-2021.10) 10.3.1 20210824 (release), GNU ld (GNU Arm Embedded Toolchain 10.3-2021.10) 2.36.1.20210621) #6 Tue Sep 26 06:53:24 UTC 2023 CPU: ARMv7-M [411fc271] revision 1 (ARMv7M), cr=00000000 CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache OF: fdt: Machine model: NXP IMXRT1050-evk board Reserved memory: created DMA memory pool at 0x81f00000, size 1 MiB OF: reserved mem: initialized node dmapool@81f00000, compatible id shared-dma-pool Zone ranges: Normal [mem 0x0000000080000000-0x0000000081ffffff] Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000080000000-0x0000000081efffff] node 0: [mem 0x0000000081f00000-0x0000000081ffffff] Initmem setup node 0 [mem 0x0000000080000000-0x0000000081ffffff] Built 1 zonelists, mobility grouping off. Total pages: 8128 Kernel command line: ip=192.168.1.86:192.168.1.96575.2 KiB/s done Bytes transferred = 3581995 (36a82b hex) ## Booting kernel from Legacy Image at 80007fc0 ... Image Name: Linux-6.6.36 Image Type: ARM Linux Multi-File Image (uncompressed) Data Size: 3581931 Bytes = 3.4 MiB Load Address: 80008000 Entry Point: 80008001 Contents: Image 0: 3570088 Bytes = 3.4 MiB Image 1: 11831 Bytes = 11.6 KiB Verifying Checksum ... OK ## Flattened Device Tree from multi component Image at 80007FC0 Booting using the fdt at 0x8036f9b4 Working FDT set to 8036f9b4 Loading Multi-File Image to 80008000 Loading Device Tree to 81dfa000, end 81dffe36 ... OK Working FDT set to 81dfa000 Starting kernel ... Booting Linux on physical CPU 0x0 Linux version 6.6.36 (sasha@e14) (arm-none-eabi-gcc (GNU Arm Embedded Toolchain 10.3-2021.10) 10.3.1 20210824 (release), GNU ld (GNU Arm Embedded Toolchain 10.3-2021.10) 2.36.1.20210621) #32 PREEMPT Sat Dec 28 16:24:02 +03 2024 CPU: ARMv7-M [411fc271] revision 1 (ARMv7M), cr=00000000 CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache OF: fdt: Machine model: NXP IMXRT1060-evk board Reserved memory: created DMA memory pool at 0x81e00000, size 1 MiB OF: reserved mem: initialized node dmapool@81e00000, compatible id shared-dma-pool OF: reserved mem: 0x81e00000..0x81efffff (1024 KiB) nomap non-reusable dmapool@81e00000 OF: reserved mem: 0x81f00000..0x81ffffff (1024 KiB) nomap non-reusable memory@81f00000 Zone ranges: Normal [mem 0x0000000080000000-0x0000000081ffffff] Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000080000000-0x0000000081dfffff] node 0: [mem 0x0000000081e00000-0x0000000081ffffff] Initmem setup node 0 [mem 0x0000000080000000-0x0000000081ffffff] Kernel command line: ip=192.168.1.82:192.168.1.89:192.168.1.254:255.255.0255.0:: eth0:off Unknown kernel command line parameters "ip=192.168.1.8682:192.168.1.9689:192.168.1. 254:255.255.0255.0::eth0:off", will be passed to user space. Dentry cache hash table entries: 4096 (order: 2, 16384 bytes, linear) Inode-cache hash table entries: 2048 (order: 1, 8192 bytes, linear) mem auto-init: stack:off, heap alloc:off, heap free:off Memory: 26584K/32768K available (3282K kernel code, 180K rwdata, 868K rodata, 184K init, 97K bss, 6184K reserved, 0K cma-reserved) NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16 Switching to timer-based delay loop, resolution 333ns sched_clock: 32 bits at 3000kHz, resolution 333ns, wraps every 715827882841ns clocksource: mxc_timer1: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 637086815595 ns Calibrating delay loop (skipped), value calculated using timer frequency.. 6.00 BogoMIPS (lpj=30000) pid_max: default: 4096 minimum: 301 Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) devtmpfs: initialized DMA: default coherent area is set clocksource: jiffiesBuilt 1 zonelists, mobility grouping on. Total pages: 8128 mem auto-init: stack:off, heap alloc:off, heap free:off Memory: 26760K/32768K available (2167K kernel code, 174K rwdata, 696K rodata, 304K init, 106K bss, 6008K reserved, 0K cma-reserved) SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 rcu: Preemptible hierarchical RCU implementation. rcu: RCU calculated value of scheduler-enlistment delay is 100 jiffies. NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16 rcu: srcu_init: Setting srcu_struct sizes based on contention. Switching to timer-based delay loop, resolution 333ns sched_clock: 32 bits at 3000kHz, resolution 333ns, wraps every 715827882841ns clocksource: mxc_timer1: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 637086815595 19112604462750000 ns futex hash table entries: 16 (order: -5, 192 bytes, linear) pinctrl core: initialized pinctrl subsystem NET: Registered PF_NETLINK/PF_ROUTE protocol family imxrt1050-pinctrl 401f8000.pinctrl: initialized IMX pinctrl driver imxrt1050-pinctrl 400a8000.pinctrl-snvs: initialized IMX pinctrl driver SCSI subsystem initialized usbcore: registered new interface driver usbfs usbcore: registered new interface driver hub usbcore: registered new device driver usb pps_core: LinuxPPS API ver. 1 registered pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti < giometti@linux.it> PTP clock support registered Bluetooth: Core ver 2.22 NET: Registered PF_BLUETOOTH protocol family Bluetooth: HCI device and connection manager initialized Bluetooth: HCI socket layer initialized Bluetooth: L2CAP socket layer initialized Bluetooth: SCO socket layer initialized clocksource: Switched to clocksource mxc_timer1 NET: Registered PF_INET protocol family IP idents hash table entries: 2048 (order: 2, 16384 bytes, linear) tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 4096 bytes, linear) Table-perturb hash table entries: 65536 (order: 6, 262144 bytes, linear) TCP established hash table entries: 1024 (order: 0, 4096 bytes, linear) TCP bind hash table entries: 1024 (order: 0, 4096 bytes, linear) TCP: Hash tables configured (established 1024 bind 1024) UDP hash table entries: 256 (order: 0, 4096 bytes, linear) UDP-Lite hash table entries: 256 (order: 0, 4096 bytes, linear) NET: Registered PF_UNIX/PF_LOCAL protocol family RPC: Registered named UNIX socket transport module. RPC: Registered udp transport module. RPC: Registered tcp transport module. RPC: Registered tcp NFSv4.1 backchannel transport module. Bus freq driver module loaded Initialise system trusted keyrings workingset: timestamp_bits=30 max_order=13 bucket_order=0 fuse: init (API version 7.34) Key type asymmetric registered Asymmetric key parser 'x509' registered Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251) io scheduler mq-deadline registered io scheduler kyber registered 40184000.serial: ttyLP0 at MMIO 0x40184010 (irq = 17, base_baud = 1250000) is a FSL_LPUART fsl-lpuart 40184000.serial: Serial: Console lpuart rounded baud ratefrom 208333 to 115200 printk: console [ttyLP0] enabled PPP generic driver version 2.4.2 PPP BSD Compression module registered PPP Deflate Compression module registered usbcore: registered new interface driver rt2800usb ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver usbcore: registered new interface driver cdc_acm cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters usbcore: registered new interface driver uas usbcore: registered new interface driver usb-storage i2c_dev: i2c /dev entries driver usbcore: registered new interface driver btusb sdhci: Secure Digital Host Controller Interface driver sdhci: Copyright(c) Pierre Ossman sdhci-pltfm: SDHCI platform and OF driver helper usbcore: registered new interface driver usbhid usbhid: USB HID core driver NET: Registered PF_PACKET protocol family mmc0 bounce up to 128 segments into one, max segment size 65536 bytes Bluetooth: RFCOMM TTY layer initialized Bluetooth: RFCOMM socket layer initialized Bluetooth: RFCOMM ver 1.11 ARMv7-M VFP coprocessor found VFP: Double precision floating points are supported Loading compiled-in X.509 certificatesns Console: colour dummy device 80x30 printk: console [tty0] enabled Calibrating delay loop (skipped), value calculated using timer frequency.. 6.00 BogoMIPS (lpj=3000) pid_max: default: 4096 minimum: 301 Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) rcu: Hierarchical SRCU implementation. rcu: Max phase no-delay instances is 400. devtmpfs: initialized DMA: default coherent area is set clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1911260446275000 ns futex hash table entries: 16 (order: -5, 192 bytes, linear) pinctrl core: initialized pinctrl subsystem imxrt1050-pinctrl 401f8000.pinctrl: no fsl,pins and pins property in node /soc/pinctrl@401f8000/adc1grp imxrt1050-pinctrl 401f8000.pinctrl: initialized IMX pinctrl driver imxrt1050-pinctrl 400a8000.pinctrl-snvs: initialized IMX pinctrl driver SCSI subsystem initialized usbcore: registered new interface driver usbfs usbcore: registered new interface driver hub usbcore: registered new device driver usb pps_core: LinuxPPS API ver. 1 registered pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it> clocksource: Switched to clocksource mxc_timer1 Bus freq driver module loaded Initialise system trusted keyrings workingset: timestamp_bits=30 max_order=13 bucket_order=0 Key type asymmetric registered Asymmetric key parser 'x509' registered Block layer SCSI generic (bsg) driver version 0.4 loaded (major 250) io scheduler mq-deadline registered io scheduler kyber registered io scheduler bfq registered 40184000.serial: ttyLP0 at MMIO 0x40184010 (irq = 187, base_baud = 1250000) is a FSL_LPUART fsl-lpuart 40184000.serial: Serial: Console lpuart rounded baud ratefrom 208333 to 115200 printk: console [ttyLP0] enabled usbcore: registered new interface driver cdc_acm cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters usbcore: registered new interface driver uas usbcore: registered new interface driver usb-storage snvs_rtc 400d4000.snvs:snvs-rtc-lp: registered as rtc0 snvs_rtc 400d4000.snvs:snvs-rtc-lp: setting system clock to 1970-01-01T04:40:24 UTC (16824) i2c_dev: i2c /dev entries driver sdhci: Secure Digital Host Controller Interface driver sdhci: Copyright(c) Pierre Ossman sdhci-pltfm: SDHCI platform and OF driver helper usbcore: registered new interface driver usbhid usbhid: USB HID core driver ARMv7-M VFP coprocessor found VFP: Double precision floating points are supported Loading compiled-in X.509 certificates mmc0: SDHCI controller on 402c0000.mmc [402c0000.mmc] using ADMA mxs_phy 400d9000.usbphy: supply phy-3p0 not found, using dummy regulator mxs_phy 400da000.usbphy: supply phy-3p0 not found, using dummy regulator mmc0: new high speed SDHC card at address e624 imx-lpi2c 403f0000.i2c: use pio mode mmcblk0: mmc0:e624 SB32G 29.7 GiB ft5x0x_ts 0-0038: resolution: 479x271 input: ft5x0x_ts as /devices/virtual/input/input0 mmcblk0: p1 p2 ft5x0x_ts 0-0038: fft5x0x_i2c_Read: i2c read error. [FTS] Firmware version = 0x5 ft5x0x_ts 0-0038: fft5x0x_i2c_Read: i2c read error. [FTS] report rate is 50Hz. ft5x0x_ts 0-0038: fft5x0x_i2c_Read: i2c read error. [FTS] touch threshold is 20. at24 0-0058: supply vcc not found, using dummy regulator i2c i2c-0: LPI2C adapter registered mxsfb 402b8000.lcdif: supply lcd not found, using dummy regulator mxsfb 402b8000.lcdif: initialized ci_hdrc ci_hdrc.1: EHCI Host Controller ci_hdrc ci_hdrc.1: new USB bus registered, assigned bus number 1 mmc0: SDHCI controller on 402c0000.mmc [402c0000.mmc] using DMA ci_hdrc ci_hdrc.1: USB 2.0 started, EHCI 1.00 hub 1-0:1.0: USB hub found hub 1-0:1.0: 1 port detected input: gpio-keys as /devices/platform/gpio-keys/input/input0 cfg80211: Loading compiled-in X.509 certificates for regulatory database cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7' -keys/input/input1 clk: Disabling unused clocks Freeing unused kernel image (initmem) memory: 184K304K This architecture does not have kernel memory protection. Run /init as init process platform regulatory.0: Direct firmware load for regulatory.db failed with error -2 cfg80211: failed to load regulatory.db Mounting /proc.. Reading /proc/meminfo: MemTotal: 2676827064 kB MemFree: 2366023332 kB MemAvailable: 2294022704 kB Buffers: 0 kB Cached: 184452 kB SwapCached: 0 kB Active: 0 kB Inactive: 0 kB Active(anon): 0 kB Inactive(anon): 0 kB Active(file): 0 kB Inactive(file): 0 kB Unevictable: 180452 kB Mlocked: 0 kB MmapCopy: 116120 kB SwapTotal: 0 kB SwapFree: 0 kB Dirty: 0 kB Writeback: 0 kB AnonPages: 0 kB Mapped: 0 kB Shmem: 0 kB KReclaimable: 504688 kB Slab: 22202808 kB SReclaimable: 504688 kB SUnreclaim: 17162120 kB KernelStack: 240224 kB PageTables: 0 kB SecPageTables: 0 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 1338413532 kB Committed_AS: 0 kB VmallocTotal: 0 kB VmallocUsed: 0 kB VmallocChunk: 0 kB Percpu: 0 kB VmallocChunk: 64 kB Done Hello, IMXRT105X_NXPEVK-Linux! mmc0: new0 highkB speedPercpu: SDHC card at address 0007 mmcblk0: mmc0:0007 SD8GB 7.42 GiB mmcblk0: p1 Hello, IMXRT105X_NXPEVK-Linux! Hello, IMXRT105X_NXPEVK-Linux! 32 kB Done Hello, IMXRT105XIMXRT10XX_NXPEVK-Linux! Hello, IMXRT105XIMXRT10XX_NXPEVK-Linux! Hello, IMXRT105XIMXRT10XX_NXPEVK-Linux! .... |