erm33_mailbox_t Struct Reference

Cross-core progress block backed by a fixed shared-SRAM address. More...

#include <ereader_m33.h>

Data Fields
volatile uint32_t	magic
	M85 stamps k_erm33_magic when ready.
volatile uint32_t	m33_sig
	M33 stamps k_erm33_m33_sig on boot.
volatile uint32_t	status
	Render status (erm33_const_t status codes).
volatile uint32_t	fb_base
	M33-published SDRAM framebuffer base address.
volatile uint32_t	fb_width
	M33-published framebuffer width in pixels.
volatile uint32_t	fb_height
	M33-published framebuffer height in pixels.
volatile uint32_t	fb_stride
	M33-published framebuffer stride in bytes.
volatile uint32_t	fb_format
	M33-published ra8_gfx_format_t (RGB565).
volatile uint32_t	fb_crc
	M33-folded CRC-32 over the rendered pixels.
volatile uint32_t	glyph_count
	Characters the M33 laid onto the held page.
volatile uint32_t	done
	Set to 1 by the M33 once the page is published.
volatile uint32_t	turn_req
	M33->M85: page-turn request, bumped per touch.
volatile uint32_t	turn_ack
	M85->M33: heavy-work ack for the matching turn.
volatile uint32_t	turn_done
	M33->M85: re-render published for that turn.

Detailed Description

Cross-core progress block backed by a fixed shared-SRAM address.

All fields are volatile so each core re-reads memory rather than caching a value in a register. The M85 owns magic (writer); the M33 owns every other field (writer). The M85 only reads what it does not own, and only after observing done == 1 behind a dsb.

Invariant

magic is 0 until the M85 stamps k_erm33_magic, then holds.

done is 0 until the M33 publishes the held page, then 1 forever.

On status == ok: fb_base is inside the SDRAM window, the geometry equals erm33_fb_geom_t, and fb_crc / glyph_count are non-zero.

Cycle handshake is monotone: turn_ack <= turn_req and turn_done <= turn_ack, each rising 0..k_erm33_max_turns.

Example:

volatile erm33_mailbox_t* mb = erm33_mailbox();
while (mb->done == 0U) {}        // wait for the M33 to render the held page
uint32_t crc = mb->fb_crc;       // CRC-32 of the SDRAM framebuffer pixels

See also

erm33_mailbox()

Since

0.1.0

Definition at line 228 of file ereader_m33.h.

Field Documentation

done

volatile uint32_t erm33_mailbox_t::done

Set to 1 by the M33 once the page is published.

Definition at line 239 of file ereader_m33.h.

Referenced by cpu1_fail(), cpu1_run_reader(), prep_mailbox(), and wait_for_done().

fb_base

volatile uint32_t erm33_mailbox_t::fb_base

M33-published SDRAM framebuffer base address.

Definition at line 232 of file ereader_m33.h.

Referenced by main(), prep_mailbox(), publish_page(), and verify_page().

fb_crc

volatile uint32_t erm33_mailbox_t::fb_crc

M33-folded CRC-32 over the rendered pixels.

Definition at line 237 of file ereader_m33.h.

Referenced by emit_cycle_verdict(), main(), prep_mailbox(), publish_page(), run_mode_switch(), and verify_page().

fb_format

volatile uint32_t erm33_mailbox_t::fb_format

M33-published ra8_gfx_format_t (RGB565).

Definition at line 236 of file ereader_m33.h.

Referenced by prep_mailbox(), publish_page(), and verify_page().

fb_height

volatile uint32_t erm33_mailbox_t::fb_height

M33-published framebuffer height in pixels.

Definition at line 234 of file ereader_m33.h.

Referenced by prep_mailbox(), publish_page(), and verify_page().

fb_stride

volatile uint32_t erm33_mailbox_t::fb_stride

M33-published framebuffer stride in bytes.

Definition at line 235 of file ereader_m33.h.

Referenced by prep_mailbox(), publish_page(), and verify_page().

fb_width

volatile uint32_t erm33_mailbox_t::fb_width

M33-published framebuffer width in pixels.

Definition at line 233 of file ereader_m33.h.

Referenced by prep_mailbox(), publish_page(), and verify_page().

glyph_count

volatile uint32_t erm33_mailbox_t::glyph_count

Characters the M33 laid onto the held page.

Definition at line 238 of file ereader_m33.h.

Referenced by main(), prep_mailbox(), publish_page(), and verify_page().

m33_sig

volatile uint32_t erm33_mailbox_t::m33_sig

M33 stamps k_erm33_m33_sig on boot.

Definition at line 230 of file ereader_m33.h.

Referenced by cpu1_run_reader(), prep_mailbox(), and wait_for_m33_sig().

magic

volatile uint32_t erm33_mailbox_t::magic

M85 stamps k_erm33_magic when ready.

Definition at line 229 of file ereader_m33.h.

Referenced by prep_mailbox().

status

volatile uint32_t erm33_mailbox_t::status

Render status (erm33_const_t status codes).

Definition at line 231 of file ereader_m33.h.

Referenced by cpu1_fail(), cpu1_run_reader(), prep_mailbox(), and verify_page().

turn_ack

volatile uint32_t erm33_mailbox_t::turn_ack

M85->M33: heavy-work ack for the matching turn.

Definition at line 241 of file ereader_m33.h.

Referenced by prep_mailbox(), run_handoff_cycle(), and wait_for_ack().

turn_done

volatile uint32_t erm33_mailbox_t::turn_done

M33->M85: re-render published for that turn.

Definition at line 242 of file ereader_m33.h.

Referenced by emit_cycle_verdict(), m85_wait_turn_done(), prep_mailbox(), and run_page_turns().

turn_req

volatile uint32_t erm33_mailbox_t::turn_req

M33->M85: page-turn request, bumped per touch.

Definition at line 240 of file ereader_m33.h.

Referenced by m85_wait_turn(), prep_mailbox(), and run_page_turns().

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The documentation for this struct was generated from the following file:

• examples/ek_ra8d2/hw_pending/ereader_m33/inc/ereader_m33.h