FreeCalypso > hg > freecalypso-tools

annotate target-utils/libprintf/README @ 607:d5abcbbf7432

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scripts/gtm900[bp]-ffs-clean: remove some more wrong files An earlier version of GTM900-B firmware has been found in the wild that still has MFW&BMI layers included (producing files under /mmi), as well as enlarged /pcm/L[DMR]N files. These files are wrong for FreeCalypso fw and thus need to be cleaned out.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 11 Feb 2020 21:27:40 +0000
parents e7502631a0f9
children
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e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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1 The present libprintf is a very light printf implementation that is well-suited
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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2 for simple bare-metal programs like loadagent; in the present case it overrides
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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3 the much heavier printf implementation in newlib. Programs like the present
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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4 loadagent only need printf in order to scribble on the serial console port,
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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5 and the most sensible implementation is to have the "character output" function
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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6 from the guts of printf point directly to the physical UART output routine, or
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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7 a trivial wrapper that turns \n into \r\n. In contrast, newlib's version would
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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8 pull in the complete FILE table infrastructure and malloc etc - maybe OK for
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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9 more complex embedded programs that use those facilities for other things under
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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10 a bona fide RTOS, but it would be disgusting to pull that stuff in for a
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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11 minimal program like ours.
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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12
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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13 The present printf implementation has been used earlier by the same author
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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14 (Michael Spacefalcon) in the StarMON family of PowerPC bootloaders, and in my
e7502631a0f9 initial import from freecalypso-sw rev 1033:5ab737ac3ad7
Mychaela Falconia <falcon@freecalypso.org>
parents:
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15 MC68x302-based SDSL CPE devices (Hack-o-Rocket and OSDCU).