armstub7: Major refactoring and size improvements#117
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- The bootstub has been completely rewritten taking advantage of the Thumb-2 instruction set, which results in major space gains - Res0 bits of NSACR are no longer set (supersedes #85) - CNTVOFF is set to zero, now consistent with armstub8 (supersedes #113) - SMC instructions are now disabled, now consistent with armstub8 - ACTLR is now configured to allow Non-secure access to several CPU configuration registers (CPUACTLR/CPUECTLR/L2CTLR/L2ECTLR/L2ACTLR), which makes it possible to e.g. enable Spectre v4 mitigations directly in the kernel without needing a separate bootstub variant (potentially supersedes #115) Free space in each affected bootstub after this commit: armstub7.bin: 108 bytes armstub8-32.bin: 104 bytes armstub8-32-gic.bin: 44 bytes (!)
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No worries, I imagine with the current events it's difficult to find time/resources for anything.
That is correct, SMC instructions are no longer allowed when using the stub. This makes it consistent with the 64-bit stub, which has never allowed SMCs either.
I was puzzled by the comment as well, but after some digging I discovered it was just copypasted from u-boot's own SMC handler. I believe u-boot does not use SMC on Raspberry Pi, as that would require loading a "kernel" into address 0 (which would bypass the armstub, so even if it does this change doesn't affect it anyway). I haven't found any evidence of |
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Thanks - that makes a lot of sense. I'll probably look at it for a bit longer, trying to pretend I understand it all, then merge it. |
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Any concerns, @popcornmix? |
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Let's give it a try. The extra space will be nice to have. |
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I'll grab the generated header for the firmware. |
See: raspberrypi/tools#117 firmware: Revert sdcard: Reduce SD read overhead firmware: arm_loader: Add GET/SET_VPU_VECTOR mailbox calls
See: raspberrypi/tools#117 firmware: Revert sdcard: Reduce SD read overhead firmware: arm_loader: Add GET/SET_VPU_VECTOR mailbox calls
- firmware: Unicam: Request frequency of 250MHz when running camera use cases - firmware: arm_loader: Fix UART unmapping - firmware: uart1: Revert to the old core-frequency-locking method See: #1267 - firmware: arm_loader: Provide a sensible device_tree_end default See: #1259 - firmware: mmal_ril: Fix size reported on ENOSPC error See: #1269 - firmware: hvs: Trigger the EOLn timer at the field rate when interlaced See: #1227 - firmware: bootloader_state: Add support for a custom TFTP prefix parameter - firmware: arm_loader: GIC stub => 2711 stu - See: #1255 - firmware: arm_loader: Add os_prefix option See: raspberrypi/linux#3237 - firmware: Add support for arbitrary memory specification - firmware: arm_loader: Fix explicit kernel name handling See: #1277 - firmware: Added a new display power mailbox call - firmware: Update display_power gencmd with optional display id See: raspberrypi/linux#3050 - firmware: Remove legacy pkgconfig to avoid Mesa conflicts See: raspberrypi/userland#585 - firmware: Update display_power gencmd with optional display id - firmware: sysman: Fix unsafe check for h264 being enabled See: popcornmix/omxplayer#749 - firmware: platform: Reduce absolute microvolts threshold to 500000 - firmware: tv_server: Also initialise ts queue on composite See: https://forum.kodi.tv/showthread.php?tid=348205 - firmware: Loop to init hotplug - firmware: hdmi: Change HDMI state machine and BVB clocks as turbo clocks - firmware: hdmi: Add EOF timeout to unjam failed mode changes - firmware: platform: Differentiate between boostable and turbo clocks - firmware: arm_dt: Set WL_ON and BT_ON from .dtb - firmware: Fixup chosing of bit depth in legacy graphics See: raspberrypi/linux#3331 - firmware: vec: Setup WideScreen Signalling outside of copy protection See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=256489 - firmware: Add global reset mailbox - firmware: 2711: De-couple start.elf clock setup from the bootloader - firmware: scaler: Correct defines for SCALER_POS0_START_Y_[MASK|SHIFT] (HVS4) - firmware: platform: Fix missing HDMI PHY power down bit - firmware: Reduce voltage as part of DVFS - firmware: arm-loader: Inherit 2711 mac-address from the bootloader See: http://git/vc4/vc4/merge_requests/687 - firmware: arm_loader: Respect all required frequencies when throttling - firmware: Fixup vcgencmd display_power return values - firmware: platform: Allow fixed voltage with avs_disable=1 - firmware: EMMC: Use PLLD for EMMC for 250MHz host-clock See: #1289 - firmware: platform: Round down effective frequencies when they exceed max See: #1290 - firmware: arm_loader: Pass video mode via kernel command for composite See: #1285 - firmware: Fix lens shading table generation buglet See: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=190586&start=75#p1534672 - firmware: hdmi: Use RB2 timing for 2560x1440@60 if pixel clock is 241.5 MHz - firmware: arm_dt: Look for ethernet0 before ethernet - firmware: arm_dt: Set PCIe dma-ranges from memory size - firmware: hdmi: HDMI SM clock must not run slower than audio MAI clock See: #1295 - firmware: arm_loader: Pass video mode via kernel command for composite (master) See: #1285 - firmware: power: Use Pi4 PMIC values on Pi3+ - firmware: Fix filtered handling of array variables See: #1296 - firmware: Update libfdt to v1.5.1+ See: raspberrypi/userland#582 - firmware: dtoverlay: Extend DT parameter syntax - firmware: memorymap: Include FW revision in start.elf - firmware: Fixup for vcgencmd display_power See: #1224 - firmware: Add hdmi_wifi_pixel_freq_adj config option - firmware: Revert mmal: Support 64 bit clients See: raspberrypi/userland#586 - firmware: arm_dt/dtoverlay fixes for ARM side camera driver power control - firmware: arm_ldconfig: Support multiple initramfs files See: #1318 - firmware: Add support for backlight enable - firmware: master: arm_ldconfig: Support multiple initramfs files See: #1318 - firmware: power: Make pmicrd/pmicwr available to all - firmware: platform: Only throttle down from arm_freq - firmware: platform: Bump desired ring osc to 3.7 on Pi3/CM3 - firmware: arm_loader: Add 2ms delay before resetting SD_IO - firmware: isp/tuner: Resetting to a lamp mode cancels manual_gains_used_ - firmware: board_info: Fix uninitialised phy_addr handling in network boot - firmware: IL video_decode: Default to H264 as MPEG4 isn't supported - firmware: IL egl_render: Fail the create on Pi4 - firmware: arm_dispmanx: Column pitch for YUV10COL is in lines not bytes - firmware: platform: 2711: Also add chicken bits to dvfs voltage - firmware: MMAL / video_render: Allow column stride to be set on column formats - firmware: vc_image/video_decode: Move +16 lines for di_adv from vc_image to decoder - firmware: platform: 2711: Support overclocking gpu frequencies See: #1290 - firmware: gencmd: Fix measure_clock name for CLOCK_OUTPUT_108 - firmware: mmal isp: Remote alignment requirements for RGB24 formats - firmware: Add missing flags for VC_IMAGE_PROP_YUVUV_4K_CHROMA_ALIGN - firmware: platform: Compromise on gpu overclock settings See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=262649&start=100#p1610362 - firmware: Add the ability to export labels from overlays - firmware: loader: 4-byte align initramfs blocks See: #1318 - firmware: vd3/video_decode: Do not add 16 lines of context when video is 1920 tall See: #1334 - firmware: Allow use of 24 bit framebuffers See: #1338 - firmware: arm_loader: Add non-os_prefix cmdline.txt fallback - firmware: board_info: Set board-info memory size according to SDRAM mode registers - firmware: arm_loader: Treat min frequencies as optional See: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=264786 - firmware: arm_loader: Add overvoltage_delta for manufacture tests - firmware: Support Isp stats and params - firmware: arm_loader: Make EMMC2 dma-ranges patch more tolerant - firmware: bootromfs: Delete unwanted assert - firmware: usb_eth: Increase timeouts for TFTP requests and retransmit ACK - firmware: isp component: rtos_common_mem: Fix handle acquire usage with wrap handles - firmware: il: video_render: Require 4k chroma alignment on YUVUV transpose See: #1334 - firmware: vc_image: Don't align the YUVUV pitch to SDRAM pages if not aligning to 4k See: raspberrypi/linux#3492 - firmware: isp component: rtos_common_mem: Fix smallalloc test in mem_handle_acquire_if_valid - firmware: platform: 2711: Make chicken-bit pip size vary with pmic quantum - firmware: USB device boot for CM4 - firmware: arm_loader: Add SET_LAUNCH_VPU1 mailbox message - firmware: il: camera: Add config.txt param awb_auto_is_greyworld for NoIR camera See: #1167 - firmware: arm_loader: Provisional support for high peris - firmware: arm_loader: Only add margins to cmdline if non-zero - firmware: clock: Support clock_measure_pll on pi0-3 - firmware: platform: Back to CLOCK_PLL_CHAN_CPER for emmc on pi0-3 - firmware: gpu_server: Fixup after LAUNCH_VPU1 commit - firmware: power: Add a notch to compensate for trim on 2835 - firmware: isp/tuner: Resetting to a lamp mode cancels manual_gains_used_ (master) - firmware: armstubs: Rebuild with latest source - firmware: arm_loader: Avoid resetting the GPIO expander - firmware: vcos_genversion: Fix up legacy variant names - firmware: dtoverlay: Add overlay_map functionality See: raspberrypi/linux#3520 - firmware: isp_tuner: Add in the slave AWB tuner handling - firmware: arm_dt: Apply os_prefix to device_tree= files - firmware: clock_2711: Fix PLL analog setup - firmware: board_info: Also include CM3+ for pmic trait See: https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=267576&start=25#p1643032 - firmware: Switch to building from common firmware branch - firmware: isp: make AGC metering respect the (digital zoom) crop region - firmware: Avoid linking in khronos on Pi4 - firmware: clock: Reset PLLC after switching VPU to OSC - firmware: arm_loader: Make 4GB available if arm_peri_high - firmware: arm_loader: Complete arm_peri_high support See: #1374 - firmware: board_info: Split Model B into rev1 and rev2 See: raspberrypi/linux#3537 - firmware: power: Clamp voltage to platform limits for all power supplies - firmware: isp: Ensure lens shading (LS) is enabled when a valid LS table is received - firmware: otp: Fix advanced boot row definition - firmware: bootcode: Fix issue booting with webcams - firmware: isp: fix ISP component to return non-zero focus FoMs - firmware: Fix for IMX477 focal length, f_number and aperture - firmware: Update firmware for USB MSD boot - firmware: platform: Fix overflow on high arm overclocks - firmware: video_encode: Add option to include header bytes with frame - firmware: DSI display: Close I2C handle if the display doesn't probe - firmware: mmal/vc: Add mapping for OMX_IndexConfigBufferStall / MMAL_PARAMETER_VIDEO_STALL_THRESHOLD See: https://www.raspberrypi.org/forums/viewtopic.php?f=70&t=273123&p=1655481 - firmware: hdmi: Request an I2C interrupt for EDID reading - firmware: i2c: Move using_interrupt flag into periph_setup - firmware: camera: Latency reduction for captures - firmware: IL camera fixes for reduced startup time - firmware: mmal_ril: Correct a use of portdef.video to portdef.image - firmware: vc_image: SDRAM page alignment is optional for YUV10_COL See: https://forum.libreelec.tv/thread/21985-noise-artefacts-when-playing-back-4k-hevc-video-on-rpi4-le-9-2-1-no-problems-on/ - firmware: imx477: Correct the logic for extending hblank on long exposures - firmware: il: isp: Ensure HR output is active and ISP is open before starting a frame - firmware: isp_ctrl: Fail in start_[raw|yuv]_frame if ISP is not idle See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=275489 - firmware: vcfw: Fix PMIC max voltage See: https://forum.libreelec.tv/thread/22097-libreelec-leia-9-2-3 - firmware: ISP raw14 and mono input, 16bpc YUV output. Camera subsystem not messing with GPIO0 - firmware: isp: fix assert from initial setting of ISP denoise parameters - firmware: arm_ldconfig: Don't pad initramfs files See: #1395 - firmware: board_info: Add and use BT_FLOWCONTROL trait - firmware: logging: Add missing checks for uart_output_enabled - firmware: host_applications: Install debug_sym.h - firmware: logging: Inherit uart_2ndstage config from the bootloader - firmware: Fix Pi4 regression in previous build - firmware: platform: Resolve BT flow control contention See: Hexxeh/rpi-firmware#227 - firmware: hdmi: Limit the valid CEA modes to those defined in the table See: https://forum.libreelec.tv/thread/22135-regression-raspberry-pi-3-hdmi-output-broken-after-upgrade-to-9-2-x - firmware: imx477: Add switch to allow switching of on-sensor DPC - firmware: hdmi: Set HD_CTL_WHOLSMP and HD_CTL_CHALIGN_SET See: https://forum.kodi.tv/showthread.php?tid=354589 - firmware: arm_ldconfig: Honour the kernel8 text offset See: #1415 - firmware: jpeghw: Skip repeated 0xFF padding bytes between markers See: RPi-Distro/vlc#8 - firmware: arm_loader: Allow interlaced HDMI modes from FKMS See: raspberrypi/linux#3698 - firmware: arm_loader: Limit rather than reject boosts with disable_auto_turbo - firmware: i2c: Clearing the TA bit may time out See: #1422 - firmware: arm_loader: Add an accelerated memmove - firmware: arm_loader: memmove kernel to preferred text_offset See: #1421 - firmware: filesystem: Fix GPT regression on USB after SD fix See: #1420 - firmware: arm_loader: Don't enable the ARM USB IRQ See: raspberrypi/linux#3703 - firmware: hdmi: Remove M2MC/BVB min turbo clock request - firmware: IL: camera: Fix stereoscopic pool allocations - firmware: arm_loader: Add support for double clock/pixel_rep for FKMS See: raspberrypi/linux#3725 - firmware: scalerlib: Set the default chroma location for YUV10 to match 8bit - firmware: scalerlib: Set chroma_vrep correctly for YUV10COL - firmware: isp: check the hi-res resize filter mode when the input crop changes - firmware: arm_loader: Knock 1.7 seconds off boot time See: #1375 - firmware: Imx477 external sync signals - firmware: bootloader: Some tweaks for LED, UART, USB timeouts - firmware: platform: Avoid vco issue with low arm_freq_min on Pi0-3 See: #1431 - firmware: arm_loader: Don't try to load to 0 a.k.a. NULL See: #1445 - firmware: armstub7: Configure the top 32 STB interrupts - firmware: dispmanx: Remove elements cleanly that are totally offscreen negatively See: raspberrypi/linux#3735 - firmware: hdmi: Set the altered mode, not the caller's mode See: #1446 - firmware: dt-blob: Declare CM4 GPIO expander pins - firmware: clocks: Make frequency_t 64-bit - firmware: Revert frequency_t: Make 64-bit - firmware: ISP/tuner: Increase max exposure time for fixed ISO modes on IMX219 and 477 See: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=281603 - firmware: sdhost_arasan: Ignore DCRC after CMD12 See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=282928 - firmware: firmware: frequency_t: Make 64-bit - firmware: pi4: allow pllb changes while running See: #1431 - firmware: board_info: Give the CUSTOM boards the PMIC_NCP6343 trait - firmware: dispmanx/displays: Allow both DPI and DSI displays simultaneously - firmware: imx477: Release the I2C semaphore once finished, not before - firmware: clock: Allow overclocking pllb See: raspberrypi/linux#3823 - firmware: hdmi/edid: Reduce the bias to all but the first detailed timing - firmware: hdmi/edid: Add option to ignore any odd horizontal timings on Pi4 - firmware: sdcard: Hybrid MBR - only select GPT if it is the first primary partition See: #1465 - firmware: audioplus: Avoid broken audio when requesting hdmi audio device when using composite display See: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=283639 - firmware: platform: Add support for SCB clock and set to 250MHz - firmware: Revert arm_loader: Move first call to set_turbo after arm->start - firmware: arm_ldconfig: GZIP-compressed ARMv8 kernel support - firmware: arm_ldconfig: Restore the fallback load address See: #1467 - firmware: ilcamera: Disable timeouts on trigger sink devices - firmware: genet: Flush RBUF/TBUF and clear mac-address on stop See: raspberrypi/linux#3850 - firmware: dmalib: Add support for 40-bit 2d memcpy - firmware: sdcard: Reduce SD read overhead - firmware: sdhost_arasan: Increase time threshold before suspend - firmware: video_decode: Only shutdown codec on both ports being disabled - firmware: vc_image_helper: Avoid misaligned exception due to uninitialised pointer - firmware: arm_loader: Make arm clock accesses only see their own boosts See: #1469 - firmware: arm_loader: enable simple_fb iff there is a display See: raspberrypi/linux#3878 - firmware: arm_loader: Mark V3D early boost as for the ARM See: #1469 - firmware: arm_loader: Update armstubs with those from PR 117 See: raspberrypi/tools#117 - firmware: Revert sdcard: Reduce SD read overhead - firmware: arm_loader: Add GET/SET_VPU_VECTOR mailbox calls - firmware: arm_ldconfig: Don't invalidate the dcache for most of memory See: #1445 - firmware: arm_loader: Allow arm to see force_turbo and uart boosts - firmware: hdmi: Timeout HDMI EDID reads - firmware: pwm_sdm: move modulator to VPU0 See: https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=195178&p=1723639 - firmware: Add tryboot mechanism to provide a fallback if an OS upgrade fails - firmware: camplus: stills_denoise: Release the VRF between iterations - firmware: vc_image: Further fixup of fix_alignment See: #1334 - firmware: arm_loader: Support large PCIe window with <8GB RAM See: https://www.raspberrypi.org/forums/viewtopic.php?p=1759627#p1759627 - firmware: filesys: Close the brfs from filesys_power(..., 0) - firmware: platform: Avoid vco issue with low arm_freq_min on Pi0-3 See: #1431 - firmware: video_encode: Allow level 5.0 and 5.1 See: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=291447 - firmware: xhci: Don't reset BCM2711 XHCI from filesys in start.elf - firmware: bootcode.bin: Add support for tryboot - firmware: Switch DA9121 PMIC to PWM mode when ARM > 600 MHz - firmware: arm_dt: Handle parent interrupt controllers when masking - firmware: config: Add cm4 and pi400 config section filters - firmware: MMAL/IL/ISP component: Set the ISP boost frequency once on open - firmware: sdcard: Remove legacy NOOBS support to support booting from primary partition 4 - firmware: arm_loader: Move 2711 RAM to PCIe address 16GB - firmware: video_decode: Add parameter to disable timestamp validation - firmware: Imx477 camera tuning fixes See: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=291032#p1770287 See: https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=291032&start=25#p1771066 - firmware: Use DMA40 for PWM audio - firmware: imx477: Replace existing 720p120 mode with a new 1332x990 120fps mode - firmware: arm_loader: Allow max_framebuffers=0 to disable framebuffers See: #1507 - firmware: dmalib: Allow sdcard to borrow channel 6 See: #1511 See: Hexxeh/rpi-firmware#251 See: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=294932 - firmware: DSI interrupt fixes, and HDMI SM clock for deep colour - firmware: dmalib: Keep 40-bit DMA clear of L2 alias - firmware: audioplus: Fix hang when switching destination See: #1516 - firmware: HAT/I2C updates - firmware: MMAL/IL: Add support for the 16bpp Bayer/Grey raw 10/12/14 formats - firmware: Revert firmware: HAT/I2C updates - firmware: firmware: MMAL/IL: Add support for the 16bpp Bayer/Grey raw 10/12/14 formats - Firmware: undo previous reverts

My motivation for this PR is #114 (comment), pointing out a critical lack of space in the armv7 bootstub which is preventing new features and bugfixes from being implemented. Here's a summary of the changes (I might have missed some, though):
The free space in each bootstub built from armstub7.S is now as follows:
Successful testing has been carried out on Raspberry Pi 2 (original revision with Cortex-A7), Pi 3, as well as Pi 4; respectively.
I'm also providing the raw disassembly of these stubs, in case anyone is curious about it.
Any further comments (such as pointing out mistakes I might have introduced) are very much appreciated.